You must be added by the person to their contacts. When they already added you, either chat or call will be available.

Messages are temporarily stored in your browser memory, not on the server. Upon the browser exit, everything will be lost.

Yes, you can go open the ⚙ button, and turn the checkbox on "Contacts Only Call" or "Contacts Only Chat". Then update the profile. When you enable this, you will receive chats or calls publicly, but if they haven't added you yet, you might not able to answer their chat or call.

You can add someone to be your contact by clicking the small (+) button. You can remove the contact in profile menu.

You can go to the donation page by clicking the $ button on the menu. Thank you!