Okay if I were to switch to plastisol ink and I don't have a curing oven or a flasher how do I cure it?

You could use a heat gun along with a temp gun. It'd be time consuming though. Or use the temp gun to flash it then final cure on a heat press. Again, not the ideal way.

These might help:

https://www.youtube.com/watch?v=Exa-ZPfqYJg

https://www.youtube.com/watch?v=2ADPL-R70gM

https://www.youtube.com/watch?v=-iJUi2skGz8