Terra Speed 40mm & Hookless Rim?

Firstly, you really have to trust your mechanic . Or find another one. The other thing that’s cool is Google.

That said, it’s always important to check the manufacturer however in Continental’s case, their tubeless tires are hookless unless printed otherwise (see previous GP5000 sidewalls as an example).

Finally, be mindful of tire pressure recommendations. Exceeding 130% of max pressure recommended is a guarantee tire blow off.