I'm not sure what "apex" refers to in this context. Since this post appears in the forum dedicated to Refinitiv Data Platform, I assume you're using RDP. In this case you can use your RDP credentials to access API Playground, which allows you to explore the endpoints available on RDP and access the documentation for those endpoints. The endpoint to retrieve historical market data is named "historical-pricing", and the view you want from it is named "interday-summaries". You may also want to check out the article titled "Comparison of RDP Libraries for Python vs. Python/requests direct call for Refinitiv Data Platform", which discusses the retrieval of data from RDP in Python using RDP Library vs. using RDP REST API, and provides examples of retrieving historical pricing data from RDP.
If you're using other Refinitiv products or services, then please specify which one you use.