if its what i think it is, then theres two possibilities.
620 Kodak film is just 120 film spooled differently. So firstly to use these cameras, in a film loading closet, 120 Medium Format film needs to be unspooled and reloaded onto an original 620 spool, since the spool size is narrower on the Kodak for proprietary reasons. After that, it can be cycled through the camera normally. To actually shoot it can be difficult since the shutter speed is fixed to approx 1/50th (or pinned open in bulb mode) with only two aperture settings of f/11 or f/16 only. This makes choosing an appropriate film speed very important to conform to this. Outdoor shooting is the cameras only strength
Since its 120 film spooled onto a 620 spindle, the numbers in the red window might not line up, so you would need to keep track of how many turns of the film advance handle is required to completely pull the next frame through. That is unless you want to try double exposures.
The second possibility is to, again, have a 620 spindle and taping a 35mm film roll in the feed. The film has to be quite centred and itll result in an ultrawide aspect ratio alongside 'sprocket hole' photography and overlapping double exposures between frames being achieved. However, the red circle at the back of the camera needs to be taped over to avoid light leakage, since its probably itll just ruin the film.
All loading for these cameras should also be done in a film closet or inside a bag too, again, to avoid contaminating the entire roll
If you know all this, then Brownie cameras can be fun, just dont expect too much out of it. I liked doing portraits with them since the 120 film resolution is impressively detailed. However much of that is lost due to the window glass lens, but your turreting setup should make creamier results
