Covid Vaccination e-Verification for Travel

[MagellanXP]

My wife and I will be arriving in Portugal this coming March (2022) and shortly there after arriving in England, then the Netherlands and several other EU countries.  In the United States we do not have a federal system for I.D and vaccine verifications. Unlike the EU Digital Covid Certification, the individual States are accepting an assortment of APPs for secure, valid vaccination I.D's. We reside in Florida which is suppose to accept TRAVWELL as the APP,  however, it indicated non-eligibility and did not accept us.  I understand the EU Digital Covid Certification does allow U.S citizens to enroll, but the application must be completed in Europe at the designated locations.  Since we are not physically in Europe, it would appear this avenue is closed to us. However,  If there is actually a way to enroll from the United States we would appreciate learning how it can be done.  According to the latest information from Portugal, upon our arrival, if we do not have EU e-verification, our status will be categorized  'as unvaccinated' and would have to be tested prior to entry.  How can non-EU members enroll in the Digial Covid Certification?