Along with numerous other EU countries, the Czech Republic is also lifting all entry restrictions for its own citizens and international guests. No forms to fill out or proof of vaccinations or recovery are required.
The Czech Republic is thus in line with the approach taken by numerous EU countries, which have relaxed their entry requirements or restored them to the status they were in before the corona pandemic. You don't have to fill out a PLF form for the Czech Republic. You no longer need proof that you have been vaccinated or have recovered.
During the Corona pandemic, this EU member repeatedly closed the borders to a large extent. However, some of the measures went too far for the supreme court, so that they were overturned several times. There was a temporary regulation that de facto meant that foreigners could only enter without quarantine if they could prove three vaccinations against Covid-19. However, this proved to be not very practical, so that after a very short time it was abandoned.