No. Gem balances are stored on Supercell servers, so a website cannot change them. An animation that claims to connect, inject resources or perform a human verification is not an operation inside the game.
How to recognize a fake generator
Watch for artificial counters, fake comments, required downloads and forms asking for a login code. Leave any page that promises unlimited resources or asks you to install an app to “verify” your identity.
If you shared a login code
Secure the email address linked to your Supercell ID immediately and contact official support from inside the game. Never pay an intermediary claiming they can recover the account.