Good day, Shaaan! I am not entirely sure what online meeting you mean. Is it a session to get to know someone/the programme?
For most meetings, you will receive an e-mail with an invitation link (for example for Microsoft Teams, Skype, Zoom or whatever) that you can click on to join the meeting.
In case you have received an e-mail and there is no link in it, or the link is not working, you can also contact the person who sent you the e-mail.
If you have further questions, please feel free to let us know. Good luck!