Can I use my at-home IPL in between my salon SHR treatments?

It is best to stay with one kind of hair removal treatment at the same time to avoid interrupting or affecting the effectiveness of your Laser hair removal treatments.
I am not sure what kind of modality they are using at the salon you are attending but, if they are using a pulse light, or laser; it is best to wait until you complete the recommended number of sesions and then 1-2 months after to use your at home device. It is also important to keep in mind that is not recommended to wax at least 4-6 weeks previous to your laser hair treatments since, it will not be effective.
If they are using other modalities like waxing, you should ask your salon to avoid making your skin "too sensitive" and to avoid hyperpigmentation.
Hope it helps!