These modules can be found on AliExpress for a few cents each if you buy 5 upwards.

It's a 12x12 mm module with the chip under the blob, typical of other cheapies like doorbell generators. The circuit shows that a resistor "programs" the delay, between 2 seconds and 1000 secondshours. It is powered by 2V to 5V so suitable for digital logic. It's effectively a non-retriggerable monostable where a low transition on the input causes the output to go low for the programmed period. There is a reference to a selectable multiplier. I think this refers to the solder jumpers which can be used to increase the delay by 8 to the power of 0 to 3. The documentation is very scarce, there is no formula provided for calculating the resistance required. A reviewer said just as much. I'm putting a link to this on the stack in the hope that someone knows more about these.

You'll need to buy $15 worth of stuff for free shipping so they could be used to top up an order to reach the threshold. I might get a few next order.