Pixel 4a 5G UW - Allow / Deny Data Roaming

 Checking your data roaming settings can be helpful, especially if you're traveling internationally and have no network connection or can't send / receive email, text, pics or videos.

From a Home screen, swipe up to display all apps.
Navigate:
Settings 
Network & internet
SIMs
.
Tap 
Roaming
 to turn on  or off .
If prompted with 'Allow data roaming?', tap 
OK
 if you agree.