STEP 2. Go to the BASIC subscription page and click on Subscribe

STEP 3. Pick a monthly subscription
STEP 4. Add coupon (type in your promo code)
STEP 5. Proceed to enter your bank card details
STEP 6. Enter your card details and click on Subscribe Now

ATTENTION! After the expiration of the first month the platform will automatically deduct the needful amount (19.90 USD). If you want to avoid this, just head over to your subscription and cancel the automatic prolongation (click on Cancel Subscription);
Here's a step-by-step video instruction of the same process:
In case of questions, please contact us at support@ab-chess.com