If it's satellite based internet, there's no way to shut it off, especially if gateway is not in the same country. Of course, the government could always patrol around looking for antennas...
Remember, this is the country where one of the charges they brought against Aung San Su Kyi during the Feb coup was importing analog two-way radios. And more broadly, people are regularly arrested and imprisoned or sometimes executed for mere possession of radio equipment.
That would literally require a man in the middle attack; the jammer should be kept between the antenna and the satellite, or very close to that position. I mean, it should be in the air.
"as well as locate them"
Possible, but not easy. A satellite dish can be buried, hidden under a camouflaging roof etc It's not like earth antennas that need the space around them free for pointing them; all they need is to see their satellite which is in the sky. One can dig a hole in the ground, put the dish down there pointed to the satellite, then when not in use park their truck above it, and good luck to the government helicopter passing above to track it. And btw, there are ways to build antennas that don't appear as such; they may offer worse performance but they do work, and satellite reflectors can be built that way too.
Or you can shoot down your enemy's satellites and screw up the orbit so he can't launch any more.
Pretty sure Myanmar can't do that.
Seriously, though, if the tech needs to be actively camouflaged and there's death penalty only for its possession, there's no way many people will use it. So it will be useless to inform and organize people, it will be useless to broadcast what's really happening inside.
Not doable unless either you are in between the dish and the satellite, or have an extremely powerful transmitter with its directional antenna pointed to the dish, where all that power is needed to cope with the fact that the maximum sensitivity of the dish is towards the satellite, not your jammer. Which also means that they need one jammer and its antenna for every dish they want to silence. That would not scale well.