From the photo alone, it’s hard to tell for certain, but if the camera was new and the mark appeared after use, it’s more likely to be a smudge or residue than a scratch. If you used canned/compressed air, that can leave residue if propellant reaches the sensor area, and it’s generally not recommended.

The good news is that you’re cleaning the protective glass/filter over the sensor, not the bare sensor itself. Start with a manual rocket blower while holding the camera opening downward so loose dust can fall out. If the mark remains, follow your wet sensor-cleaning kit instructions carefully: use minimal fluid and use each side of the swab only once.

If the mark was present from the beginning, or you’re worried about making things worse, professional cleaning is a sensible option. If cleaning does not remove it, then you may be dealing with a scratch or other damage and should contact the seller or service center.