If during registration on the platform you have chosen Free access (access with limited functionality), and now you would like to improve the access level, please do the followinf steps:
1) Click on your name next to the avatar in the upper-right corner.
2) Click on the Membership button.
3) Go to the Subscriptions tab and сlick the Change Plan button.
4) Select the access level.
5) In the form that appears, enter your data specified earlier during the registration.
6) Click Sign up.