Land.io is a carefully crafted landing page UI kit and landing page template built on Bootstrap 4, designed by Peter Finlan and developed by Taty Grassini.
in /user/themes/landio/templates/partials/login-form.html.twig and in /user/themes/landio/templates/partials/navigation.html.twig the variable {{ 'LOGIN_PLUGIN.BTN_LOGIN'|t }} is used, but I believe it should be: {{ 'PLUGIN_LOGIN.BTN_LOGIN'|t }}
in /user/themes/landio/templates/partials/login-form.html.twig and in /user/themes/landio/templates/partials/navigation.html.twig the variable {{ 'LOGIN_PLUGIN.BTN_LOGIN'|t }} is used, but I believe it should be: {{ 'PLUGIN_LOGIN.BTN_LOGIN'|t }}