What length screws to use - bike rack

[Welshbeef]

Just bought a couple of Mottez 2 bike racks - but they came without any attaching screws.

It says up to 30kg but it’s kids bikes currently.

[hyphen]

What are you bolting it into? Direct Brick? or plasterboard covered brick, or plasterboard. How thick is the frame itself?

What type of screw are you using? Anchor bolt and sleeve? Or normal screw and plug. Max weight in future?