Hello,
According to the Reference Manual MCXA175/176/185/186/255/256/265/266, MCXA176 and MCXA266 are similar.
The MCXA176 SDK contains the example "power_mode_switch" this example demonstrates the usage of low-level power to enter/exit different power modes including deep sleep mode. The example is intended for the FRDM-MCXA266; You could take this example as reference for implementing the deep sleep mode in MCXA176.
Also, this SDK contains LVGL examples as well if you need it.
To download the SDK please enter this link and search for the MCXA176: Dashboard | MCUXpresso SDK Builder and when importing the SDK in MCUXpresso search for the example in "Quick Start Panel > Import SDK examples > MCXA266 >Search for "Power_mode_Switch" example.
If you have any further questions, please let me know.
Best Regards, Luis