Hi,
the effects loop may not be the best place.
If your tuner is “true bypass” then you are likely fine.
True bypass is close to a straight wire when it’s switched out.
If there is a “buffer” then you may find some signal degradation. “Tone suck”
A clean signal path is the ideal.
An AB pedal will mute the amp while you’re tuning up.
Hope this helps. Try both ways.
Take care…