First, I would assume by "agile" you mean Scrum as Product Owner and Scrum Master are actually Scrum roles.
Basing on this assumption: to answer your question - yes, this is not prohibited for the Product Owner to also be a developer. But this can cause lack of balance. I would say, it really takes a wise man to be able to combine both roles with no significant impact on the effectiveness of the team. And definitely, this guy should be a true energiser to be able to: estimate development effort, write code, talk to team mates on technical solutions, participate in code review and testing, talk to user, talk to stakeholders, gather requirements, talk to UX guys, work out wireframes, keep backlog transparent, keep business informed on the progress, estimate business value, etc.
Also, from my own experience - combining multiple roles is causing a burn-out very quickly. So, I wouldn't recommend doing this.
Speaking about your case specifically - you don't actually have Scrum. There is no team lead role in Scrum. There should be a single Product for the team to work on. Having various applications and projects is generally not prohibited, but this should all go under the same Product and you should be able to transparently prioritise value across all the projects and apps. As an example, even working on various projects and apps, you can have your company as a product with a main value gain reflected by revenue. But this looks a bit artificial to be honest.
How do you choose which project/app you are going to be focused the next Sprint?
Product Owner is not the person which writes tickets, this is the person which prioritises value. Meaning, this person decides what to do next basing on input of various stakeholders. Are you able to decide yourself what the team is going to work on?
And to be honest, I don't see you as a Scrum Master. You definitely don't understand what is Scrum and why do you want to have it.
I would start with reading the Scrum Guide and taking an open assessment for it (it is free).