the Structure of ChatMember is :
type ChatMember struct {
tdCommon
UserID int32 json:"user_id" // User identifier of the chat member
InviterUserID int32 json:"inviter_user_id" // Identifier of a user that invited/promoted/banned this member in the chat; 0 if unknown
JoinedChatDate int32 json:"joined_chat_date" // Point in time (Unix timestamp) when the user joined the chat
Status ChatMemberStatus json:"status" // Status of the member in the chat
BotInfo *BotInfo json:"bot_info" // If the user is a bot, information about the bot; may be null. Can be null even for a bot if the bot is not the chat member
}
the Structure of ChatMember is : type ChatMember struct { tdCommon UserID int32
json:"user_id"
// User identifier of the chat member InviterUserID int32json:"inviter_user_id"
// Identifier of a user that invited/promoted/banned this member in the chat; 0 if unknown JoinedChatDate int32json:"joined_chat_date"
// Point in time (Unix timestamp) when the user joined the chat Status ChatMemberStatusjson:"status"
// Status of the member in the chat BotInfo *BotInfojson:"bot_info"
// If the user is a bot, information about the bot; may be null. Can be null even for a bot if the bot is not the chat member }But the result returned by SendAndCatch is
{"@type":"chatMembers","total_count":13,"members":[{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":1089219804},"inviter_user_id":1089219804,"joined_chat_date":1589193198,"status":{"@type":"chatMemberStatusMember"}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":781114735},"inviter_user_id":906717356,"joined_chat_date":1622183247,"status":{"@type":"chatMemberStatusAdministrator","custom_title":"","can_be_edited":false,"can_manage_chat":true,"can_change_info":true,"can_post_messages":false,"can_edit_messages":false,"can_delete_messages":true,"can_invite_users":true,"can_restrict_members":true,"can_pin_messages":true,"can_promote_members":false,"can_manage_video_chats":true,"is_anonymous":false}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":517476446},"inviter_user_id":680201368,"joined_chat_date":1589191777,"status":{"@type":"chatMemberStatusMember"}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":1020650019},"inviter_user_id":680201368,"joined_chat_date":1589191777,"status":{"@type":"chatMemberStatusMember"}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":994519125},"inviter_user_id":680201368,"joined_chat_date":1589191777,"status":{"@type":"chatMemberStatusMember"}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":1470087523},"inviter_user_id":517476446,"joined_chat_date":1605332548,"status":{"@type":"chatMemberStatusMember"}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":1254472319},"inviter_user_id":1027769782,"joined_chat_date":1637576133,"status":{"@type":"chatMemberStatusMember"}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":680201368},"inviter_user_id":680201368,"joined_chat_date":1589191777,"status":{"@type":"chatMemberStatusCreator","custom_title":"","is_anonymous":false,"is_member":true}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":746094168},"inviter_user_id":680201368,"joined_chat_date":1589191777,"status":{"@type":"chatMemberStatusMember"}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":751087862},"inviter_user_id":746094168,"joined_chat_date":1615791482,"status":{"@type":"chatMemberStatusMember"}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":906717356},"inviter_user_id":680201368,"joined_chat_date":1589191777,"status":{"@type":"chatMemberStatusAdministrator","custom_title":"","can_be_edited":false,"can_manage_chat":true,"can_change_info":true,"can_post_messages":false,"can_edit_messages":false,"can_delete_messages":true,"can_invite_users":true,"can_restrict_members":true,"can_pin_messages":true,"can_promote_members":false,"can_manage_video_chats":true,"is_anonymous":false}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":1027769782},"inviter_user_id":517476446,"joined_chat_date":1628649822,"status":{"@type":"chatMemberStatusMember"}},{"@type":"chatMember","member_id":{"@type":"messageSenderUser","user_id":1654753498},"inviter_user_id":906717356,"joined_chat_date":1622183247,"status":{"@type":"chatMemberStatusMember"}}],"@extra":"NFwmCeXQHFCqrkZTdLKakaWSsPVkypQB"}
It has no way to parse userid into structure