[Responsibility2nd]

Anytime you're at a yard sale or a junk shop, and you find one. Buy one.

The old metal ones are usually rusted, so these are best.

[faucetman]

NOT this one! No good. It has the separate vent that breaks off and the cap becomes detached from the can and is so small it is easily lost.

What you need is one of these.

https://www.thriftyfun.com/tf/Cars/Cleaning_Interior/Removing-Gasoline-from-Car-Carpet.html

never mind the article, I chose it for the photo.

Here you can see just the spouts. Shop around.
https://www.ebay.com/itm/Blitz-900302-Plastic-Gas-Can-Spout-Gas-Cans-with-Yellow-Cap-/162949748014

[packrat35]

I got 6 of the 5 gallon ones and 6 of the 2 gallon ones. I’m good!