Multi-Step Form Challenge using Angular

Everything seems to be working. One thing, it does not have validation error message on step 1. So it's kinda confusing for user when they insert invalid format in particular field, they can't go to next step (because button is disabled) without clear information what they did wrong. I know the approach of disabling button is fine, but that is not the best user experience. Instead of disabling that button, you can assign it to be a trigger for validation before go to next step. For the example, this community feedback field doesn't disable the button(for posting it). It screams invalid message when i click post with not a single character in it.