Glabella There is a little interval indicator in lower level, with various selectable intervals between 1 and 60 seconds. Do keep in mind though, that this is creating a 30fps video.
At 120s that's only 30 frames per hour, the eclipse is 2h40m end to end, which would be 2.66s of total playback at 30fps. That's quick even for an IG story or YT short.. 😉
Generally it's better to shoot more frame than you need.
If you want to capture individual frames, check out the Intervalometer app (for Android). It can literally press any button in any other app at any interval you want for as long as you want. I have tested that it can drive the Seestar app.