Concatenate link with a field on board?

I have a need to create a new column on all our boards that contain a link with a unique identifier at the end of it. I have a field in each board with the unique identifier and I just need to create a field that takes that ID and attaches it to the end of a static url. I am attempting to concatenate in a formula, but I’m getting an “illegal formula” error. Is there a way to accomplish this without needing to use the API to create all of these urls?