Simple design for an automatic portal. Works on bedrock and java

Use:
flick lever
go through
After some time it turns itself off (the exact time it takes in survival to go through a portal, and then come back)

How It Works:
The observer sends out a pulse, which powers the first dispenser (flint & steel), and then the repeater line powers the second one (lava). The offshoot repeater line powers to dispenser again to remove the lava