Can I use a prebuilt front end chatbot with custom backend/azure openai?

I’d like to add a chatbot to my wordpress website and a web app (.net hosted on azure). Are there any popular prebuilt front end chatbots that I could use with a custom backend?

I plan to use azure open ai and train it with my own knowledgebase. I’d also like the flexibility to expand moving forward so I believe I need a fully custom backend. I also like the idea of using openai api for pricing instead of paying a company for their price inflated tokens. Just don’t want to spend a lot of time/$ building a front end chatbot if there are good ones out there that I can tie into my backend.