Hi Johnny_432
Thank you for that information,
Dell do indicate the 5 beeps on that laptop indicate the CMOS battery needs to be replaced, and seeing as that is a 2015 model, the battery is 7 years old which is about the expected lifespan of a CMSO Battery.
Seeing as the beeping has stopped, wait for a day or two to see if the beeping starts again, and keep an eye on the time in Windows when you start up the laptop, if that is not correct, or the beeping returns, then you will need to replace that CMOS battery on the motherboard.