Do a diagnostic to make sure nothing is physically wrong with the camera. If the camera is damaged you will have to get it repaired. If the camera checks out as fine, then a reset would be your best option. Diagnostics can be accessed in the support tab of the members app or through your phone's device care settings.
Make sure you dont open camera app. This might cause hardware damage to lens. Ive faced this issue with my S8 plus back then. Check with the Samsung care asap. Its probably software issue
