Google Pixel 3a compatibility

Ok, so I found a long thread about this elsewhere but could not find out if there was a resolution to this?  I want to buy a Google Pixel 3a G020G but cannot find if it is compatible.  I'm beginning to suspect that no unlocked phone from anywhere else in the world will be compatible and the only phones that will work are ones purchased through your store.  Would that be correct? Trying to save some aggrivation and some money as we are all devastated by the Covid shutdown and my phone dropped and died. 😞