Amplifier Effects Loop

I've got a question regarding how to use the effects loop on my guitar
amplifier. The amp in question is a 60W 4x10 Fender Hot Rod Deville.
There's PREAMP OUT and a POWER AMP IN jacks besides two INPUT jacks.
How do I hook up e.g.. my TS7 Tubescreamer using the effects loop on
the amp?

I was thinking that too. My THD's effect's loop is line level. not
instrument level.

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