Yes, you can run all Red Panda pedals in your amp's effects loop.
Our pedals can handle line-level signals, but if you get distortion you can use our web editor to increase the maximum input level (on newer pedals). Most amp effects loops are serial, so you will use the pedal's blend knob to adjust the wet/dry balance. If your amp has a parallel effects loop, you should set the pedal's bypass mode to "kill dry", which will mute the dry signal to avoid phase issues.