The lip or rim of the topmount sink rests on top of the counter into which the sink is set.
The sink is supported by the countertop and braced but not supported by clamps on the underside of the cabinet.
Topmount sinks do not fit deeply into the cabinet and leave room for storage beneath it. Installing this type of sink is simple and does not require any special expertise.
And for easier installation, you can use glue to fix the sink on the surface of countertop without any clips and just make sure your opening hole on the countertop can let the sink bowl go inside.