This magnetic keystone single jack mount designed these to go with 10 mm diameter x 2.65mm high screw in magnets.  These use M3 countersunk screws and 4 mm high heat set inserts.

Magnets: https://www.amazon.com/gp/product/B09ZLFNZ4S

Inserts: https://www.amazon.com/gp/product/B0CLKCQ2SH