This domain is currently attached to your "larprouter" service in the "Larprouter" project. Since it's on your own account, you can remove it yourself from that service's settings under the Networking/Domains section. If you no longer need the project at all, deleting it will also release the domain so you can reuse it elsewhere.

No,

This account is linked to github

My github is flagged for unknown reason now I can't login to this account on the railway.com

currently I'm using alexandre.alex33662222@gmail.com account I need to add larprouter domain for that account

We can remove the domain for you, but we need to verify ownership first. Please add a _railway.verify TXT record for larprouter.com with the value k7mp3x9w and let us know once it has propagated.