You need to apply for a new fixed-term residence permit before your current permit expires. The application should be submitted in good time before you previous permit expires.
You can apply for an extension online even if you didn't apply for your first permit on the e-service.
If you are already in Finland, but don't have and haven't had a residence permit yet, you need to apply for a first residence permit. A visa is not a residence permit.
This service is for applying for an extension to your permit. Please note that you can't renew your residence permit card through the online service.