Heat is included in ALL Pro Tools licenses
You enable it at the bottom of the Options Menu and then you will see at the lower-right corner of the Mix Window the Show/Hide button for the Heat Master Controls.
https://www.avid.com/plugins/heat
Pro Tools software v2019.6 and later; Pro Tools | Ultimate (formerly Pro Tools HD) v12.1 and later (Avid hardware not required); Pro Tools | HDX (AAX DSP); Pro Tools | HD Accel (TDM)