I either make it straight in it. Use 8, 8oz jars and make sure to put one cup of water in the liner. Or I mix in a bowl that fit inside cover it and make sure you put one cup of water in outer liner.
I make it directly in the inner pot then transfer to storage containers after it has been in fridge for at least 8 hours. Do not stir as this breaks protein bonds and releases the whey
I use glass jars (mason or recycled). In 8+ years of weekly batches I’ve never put water in the bottom. Directly into the fridge they go. I have a tiny jar I use for the starter so it’s never contaminated. Easy.
A 3 quart liner for pot in pot in the 6 or 8 quart instant pot fits perfectly.
Instant Pot Ceramic Non-Stick Interior Coated Inner Cooking Pot Mini - 3 quart https://a.co/d/0d88hI9 
I couldn't handle the weight if I made it in the liner, I used 6 oui jars filled them with the mix put in overnight and it was ready to cover and into refrigerator in morning. Worked for me as I could lift each jar out without a problem.