Remini, which is the tech MyHeritage has licensed for this, offer 4.99 a month sub to use their existing mobile app (though this can only be used on a PC rather than a phone by using an emulator like Bluestacks). Worth noting though - the animation on MH gives you multiple options to try per picture - whereas the Remini app only offers one animation try at a photo.
Also worth noting - I signed up for the free trial last week on a burner email, and today it's offering me a years sub - including unlimited use of the animation tool - for 1/3 the price (so £77 in the UK) ... I just don't know if I could justify that cost still.
The results can range from very, very impressive to nightmarish
Naturally, I forgot to bookmark it and can't find it again, but this fee-based site is actually built on an open-source AI project that is available on GitHub. Not sure how much stuff the site had to build and bolt onto the base project, but the back end is probably command-line only, most likely based on FFmpeg like virtually every other video function in the Linux world.
If I ever find it again, I'll edit my post. I probably spotted it on Reddit somewhere.