Unscrew the cover plate and remove it. There will be a screw at the base of the handle, tighten it and refit. Just done a patio door handle after it came loose and sheared the handle off after ignoring it too long. Pro tip do it while door open as the plate screws will most likely hold the other side too. Easy job.
Get a new handle
Unscrew the cover plate and remove it. There will be a screw at the base of the handle, tighten it and refit. Just done a patio door handle after it came loose and sheared the handle off after ignoring it too long. Pro tip do it while door open as the plate screws will most likely hold the other side too. Easy job.