If I'm understanding correctly -- I only need to host my web app at example.com, but I should create a subdomain merchantA.example.com and host my apple-developer-merchantid-domain-association for merchantA at https://merchantA.example.com/.well-known/apple-developer-merchantid-domain-association. This will verify the domain example.com for merchantA

If I'm understanding correctly -- I only need to host my web app at example.com, but I should host my 2nd merchant domain association file on the subdomain merchantB.example.com at https://merchantB.example.com/.well-known/apple-developer-merchantid-domain-association. This will enable merchantB to be registered for example.com