From the PC itself you can't reset your ads, you'll need a mobile device.
Normally ads reset at a different time for everyone, in my case my ads reset when i get my daily bonus at 5pm.
To get your ads back on pc, you have to first watch an ad on your phone.
The way i do it, is i go to mission 1 / raid, kill a bot and abort the mission, usually an "Improve your mech" window pops up that you can watch for 2 tokens.
After that you can do the other 29 ads on pc.