@catalin-chitu, it seems like what the hosting company has told you is somewhat inconsistent, because first they suggested that if you get the cert yourself, you can use it with their service, and then later they apparently said this is not the case—I suppose that's what was confusing @ahaw021.
Sometimes what hosting companies tell users is different depending on the support person who answers, or depending on how the question was asked (for example "we don't support Let's Encrypt" might mean "we have never heard of Let's Encrypt", "we don't have an automated way for you to get and install LE certs", "we won't actively help you with this process", "you can get and install the cert yourself, but our infrastructure won't help you request it (or you're not allowed/able to install LE clients on our infrastructure so you have to run the client elsewhere)", "if you get the cert yourself, we can install it for you, but we can't help you get it", "as a matter of policy we don't want to install an LE cert for you", "as a matter of policy no third party certs are permitted on our service", among other possibilities!).
Anyway, I hope you're able to figure out a useful path forward. There is a pretty long list of hosting providers who support Let's Encrypt (in some way) at
As the list notes, it's also possible to use LE certificates on most VPS services if you have root access, whether or not the service provider has taken steps to actively support LE.