This is a common problem these days. We need to wear mask to protect ourselves and others. However, if you are developing Acne in the mask area, then you should start with the following.
1. Ethiglo Facewash - cleanse your face 2-3 times per day with this cleanser.
2. Epiduo Gel - Apply at night on the lesions. Just dab it onto the acne and leave it on for 30 minutes and then wash it off with plain water. As your tolerance increases, you can increase the contact time by 1 hour every few days till you are comfortable and eventually apply it overnight.
Next Steps
If you do this regularly, then your acne should improve with just the creams.
Health Tips
In case it doesn't improve with creams, consult a dermatologist near you or through practo consult because you may need to be investigated further and may require some medicines. https://www.thehealthjournals.com/acne-causes/