HELP. Inkbird Setup

I finally got my inkbird 308s in for my BPs.
But I don't know if I'm just stupid or what, but the instructions are not making sense to me. I need help to set this up please.
I've been trying for a couple hours now.
I just need to know what to set each setting to and I should be fine.
I am setting these up on 2 sterilite tubs.
PLEASE PLEASE PLEASE.

Do you have the thermostat set up like the picture that's floating around, with the probe in-between the heat source and the tub?
I usually set my thermostat for 90. But it depends on sever external factors such as room temp and thickness of tub, if there is a gap, how big the gap is, etc..and will not be consistent from person to person.
Do you have an infrared heat gun to check temps in the tubs?
Also I may be mistaken but isn't the inkbird 308 an on/off thermostat? Not a pulse proportional one?

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