Yes, you can upgrade or downgrade to a different plan, add or remove licenses to your existing plan without being charged during the trial period.
At the end of the trial period, your invoice will be calculated according to the selected plan and number of licenses for the upcoming billing cycle. You can change your plan by:
1. As the account admin, go to admin management page on the side menu
2. Select Plan & billing
3. Click on Change plan or Reactivate
4. Select your desired plan
5. Select your number of licenses
6. You will see that your invoice is issued with 0 SAR as you are not required to pay anything during the trial period