getting training signal to the amp

[Spunky99]

I'm getting ready to do my first training.

I've searched and run out of query words.
I understand you need to send the training signal to the amp and then use a device like a captorX to input to a Scarlett or other device and into Reaper or other DAW.

Here is my question:
The amp expects a guitar/bass input, not line level. So what is the best way to send/inject the signal into the input of the amp?
Levels?
Do I just copy it to a portable recorder like a Zoom and play it back and adjust the levels so it doesn't clip and record the output in Reaper?

[Doom Plugs]

Try and search for 're-amp boxes'. Re-amp boxes are the exact thing you are looking for in order to convert a line level signal from your interface back into a hi-z signal for your amp.