Why it redirects me from a custom domain to squareup.com while booking?

[olha_cs]

When booking instead of staying on my custom domain it redirects to book.squareup.com right after choosing a service. 
How to fix this?

[RobynR]

Hey @olha_cs,

Welcome to the Community. I'd be happy to assist.

Are you booking through your personal booking link or another seller's link? If you are using your personal booking link, please provide the URL so I can investigate further.