Hi
So i am addressing the problem from the start and
regarding the “GUIDED_NOGPS” as per the documentation it only accept attitude target as per link Guided Mode — Copter documentation defined in this mavlink message Messages (common) · MAVLink Developer Guide.
Solution-1: So you have to calculate the attitude targets to make the drone move to desired location in (I have no idea about this support in mavros)
Solution-2: You can set the "set Home Here → set EKF origin here " as per this link Non-GPS Navigation — Copter documentation to set the global position origin manually and then you can set the drone in “Guided” mode and use mission planner to make the drone “Fly to here” to test (Give it a very short way-point to test) .
Remember : The global heading and local heading may not align so give the way-point in the same direction drone is facing in Mission planner.
Sources :
1-> HOW TO SET EKF ORIGIN : https://www.youtube.com/watch?v=YZm6bmGDB5U
2-> Autonomous flight (Indoor Guided Mode) : https://www.youtube.com/watch?v=Gqja_gBFBuA
The system should work with optical flow as well i havent tested the same in much detail but it should work.
Caution : Do not use the compass indoor (You may experience a rotation in drone due to interference). But you can give it a try be careful. if you have different heading system then its okay.
I havent seen your logs just proving a solution on how you can use guided mode indoor.