My understanding is there are many areas of AI today. One example is ChatGPT which make use of large language model. Model means database or collection of data.
B4A (B4X) is just another programming language like Java or Python. It is not impossible to "create" an AI like this using B4X. To create a model, maybe we create a web crawler to dig all the data on the Internet. Then add some logics that can return the answer in human language. But no need to reinvent the wheel.
There are other types of AI like generative AI that can generate and recognise an image. For me, all this is just piece of software written in programming language.
To use or integrate a model, the provider usually provide API to easily integrate into app written with various programming language. We can also use B4X to communicate with the API. There are already some examples in this forum. To learn how to use it we need to study the documentation.