To fix the metadata.yaml file you need to remove the trailing commas in rtbhouse.com
YAMLError: end of the stream or a document separator is expected at line 1, column 37:
homepage: "https://www.rtbhouse,com",
^ at line 1, column 37:
homepage: "https://www.rtbhouse,com",
Looking at the URL it also has a comma instead of a pirod between rtbhouse.com
https://github.com/rtbhouse-apps/gtm-tag-template-hosted-js/blob/3a39481a8582215b21f1723980a97fb91bc917be/metadata.yaml#L1-L2
To fix the metadata.yaml file you need to remove the trailing commas in rtbhouse.com
Looking at the URL it also has a comma instead of a pirod between rtbhouse.com