lightning invoices are decodable. this means that if the server generates an invoice with an incorrect amount, you can see that the amount is wrong before making the payment. check this out:

The Lightning Invoice

Learn about Bitcoin Lightning Network invoices. Get in-depth decoding on the inner workings of payment requests in LN.

Yes thanks, I knew that. But is there something that can prevent that? Or is my request somehow cryptographically also in the invoice generator?

the safest way is to run your own lightning node ofc. do not trust, verify ✅