They are still able to import and export goods from around the world. Even US has exported goods to them (more than Canada or Mexico.) Its just that US doesn't import much from them.

https://oec.world/en/profile/country/cub?yearlyTradeFlowSele...

They have been getting free oil from Venezuela in exchange for helping the dictatorship there for the past 25 years. They then sell that oil for resources to pay the military and the top brass well fed while the population starve

Apparently they see that as preferable to becoming an American colony.

By "them" who do you refer to? Because I believe the people from Cuba haven't been to choose their govement for the past 70 years

Standing? Their population has declined by 20% in 2 years. I'd describe that more as crawling on the ground and starving.