Usually
It’s hard for me to offer guidance on questions that are usually asked at the viva.
You could search for “PhD viva questions UK” and explore the results. Adding your general research area as part of the search term might produce something more specific.
But every viva is unique and questions are always tailored by examiners to the research, the thesis and the candidate. Examiners need to explore the significant original contribution, unpick the research process and examine the capability of the candidate.
Consequently, it’s hard for someone like me without subject knowledge to suggest questions for someone – but if that candidate reflects on their research and the areas that drive examiners they will be able to identify topics to help their preparation.
There are no questions that are usually asked. There are areas that have to be explored in discussion.
Consider those areas, reflect on your research and see where that thinking leads you in your preparation.