Synchro Arts licenses purchased after April 2024 can be active on two (2) computers at a time.
You can view a list of your current active locations, and deactivate them as needed, with the "Manage" button to the right of your license code on the plugins page in your account on the website.
The Manage button is found here for each license:
Clicking the Manage button will show you a popup with your activation count, currently active computers, and "Remove" links which will deactivate a computer:
Legacy iLok license activations won't be manageable in this way, but need to be managed in the iLok License Manager app instead.