Do they ask for the digital vaccination certificate or can it be on paper for Mexicans crossing into San Diego?

They do not ask for the certificate, they only ask if you are vaccinated, they do not ask for anything else.

They didn't ask us. They just asked if we had. Once before they didn't even ask. I think that paper is enough if they question you

Thanks Xavier. So with the paper if I can pass? I couldn't download the digital

They ask you for proof that you have documents and pay $ 20.00 dollars per person and you can pass