Yes, to my knowledge that’s true.
If your motivation is legal/security requirements
For institutions that need to have the data stored on their own servers for data/legal reasons we can support them in doing that, but it costs considerably more to provide that bespoke support than using the standard server.
If your motivation is to cut costs
The PsychoJS library is open source so there’s nothing to stop you using that and exporting your data to some other server. The time spent setting that server up and maintaining it are likely to be more costly than simply paying for Pavlovia, especially once you’ve gone to the levels of ensuring the security of the server and communication (e.g. penetration testing is expensive)
So there are a range of options there for you, but Pavlovia is the cheapest and easiest, I believe
For a similar discussion see