If you want to see military aircraft use ADS-B exchange: https://globe.adsbexchange.com/ there is a filter (click the U button on the map) that will only show military aircraft. The commercial ADS-B tracking sites filter out these and many other aircraft. Enjoy.

If you are running your own receiver, you should see them on your map, especially if you are part of a MLAT network for calculating position data for aircraft that only transmit Mode-S data.

The key issue is ICAO hex to aircraft mappings, and there you'll need to either do a lookup against (often commercial APIs) or build your own registration database from public data.