OP already got “basic dns help” in the top-level responses.
Please build that foundation you mentioned out of correct information.
I only take issue with short and wrong general statements where there is really no need to double down on them.
I have no intent to reply any further.
Sure, it’s not helpful, but just because something is out of scope for the original question doesn’t mean you can reiterate objectively false statements.
They probably should have worded it like you did in your first sentence.
DNS can deal with ports.
You can use a SRV record to specify the port for applications (not browsers) that support it.
I think Cryptpad has a good forms builder. Try it here (official instance)