A catholic is not permitted to receive eucharist from a protestant church.
The only exception is if the catholic church has declared that particular church has a valid sacramental communion.
For example I have attended greek orthodox churches and have received communion.
@phil19034
“Members of the Orthodox churches, the Assyrian Church of the East, and the Polish National Catholic Church are urged to respect the discipline of their own churches. According to Roman Catholic discipline, the Code of Canon Law does not object to the reception of Communion by Christians of these churches (canon 844 § 3).”
Correct. Catholic may receive communion in one of those churches. But we are also supposed to refrain from doing so unless we can’t receive at a Catholic Church. For example: we live in Russia and the Catholic Church is hundreds or thousands of miles away. We really should not receive when simply visiting one Sunday because most of these other Churches do not want us to receive - esp the Orthodox.
God bless.