I'm a freelancer in IT, I am trying to build or willing to use a free program that can be self hosted but here are the very simple things I'm trying to accomplish:

I would like a customer to go to a landing page that they can submit a ticket (I would love for them to be able to create a profile and have their own portal where they can communicate with their own ticket(s) as well) but they enter in their issue or request, they can add attachments, and they select what service it's in regards to (Networking, Signage, CCTV, Social Media, Point of Sale, or Other and they can enter in that)

From their a ticket should push notify me either with a mobile app I have downloaded from this self hosted application, or a slack notification and this should have a portal for myself that can track open and closed tickets, I can see customers who created profiles that I can manage what equipment each site has, manage contracts that each customer has, and also can message this customer through the portal, but it doesn't have to have messaging I'm willing to forgoe that. It should also have appointment scheduling where it emails the customer when an appointment is set and date and time they can add to their calendar.

I want my customers to have a simple way to put in a request essentially, I get the notification, I can then contact them via my phone by text or call and book the appointment if one is needed.

This should be lightweight, I don't need other bells and whistles. I'm even willing to do a simple Notion template if it can achieve those objectives and/or use automations to accomplish everything.