It appears that the one that moves is on the inside.
Thanks.
A picture is worth a thousand words.
Without photos there are numerous questions and false assumptions you'll need to endure in this process.
So, here goes.
At the door latch, and there a a couple of different styles, move the lever in one direction or the other and push against the latch as if you are attempting to close the door to see if the latch may be stuck or adjusted to not open.There may be an audible response.
Some styles adjust with the door open and some with the door closed.
So to clarify, there a two glass panels, 1 is fixed and does not move freely, the other is the slider and hopefully can be freed.
If the door already appears to be raised above the bottom track and tight against the top track the rollers on the bottom are adjusted up.
Just above the lower track, in the frame of the slider may be a phillips head screw, and a hole. Leave the screw alone and insert a #2 phillips screwdriver into the hole and turn the screw counter clockwise a full turn or so, and the door should lower. If not you may have to pry the door down slightly from the top.
If there is space between both the top and bottom track, and you have a 12 to 18" heavy screwdriver, insert it at the base of the slider, in the track, where the slider and the fixed panel intersect, about a half in or so and "gently" attempt to lift the door, gradually increasing the lift.