I think it is not possible out of the box. The edx system is fixed to use one single currency at a few places. I have not used the ecommerce system though, so I might be wrong and there might be an additional feature for that. Looking into the doc, there was a mention of a "Currency list" here:
https://edx.readthedocs.io/projects/open-edx-building-and-running-a-course/en/open-release-ginkgo.master/manage_live_course/manage_course_fees.html#set-the-price-of-the-course, but I think for Hawthorn the section has been (re)moved.
However, if you are willing to modify the code, the PAID_COURSE_REGISTRATION_CURRENCY flag already uses an array with [<CURRENCY>, <SYMBOL>], but at a few places, the lookup is hardcoded to PAID_COURSE_REGISTRATION_CURRENCY[0].
You'll have to adjust the edx-platform slightly, as well as the ecommerce module. For the edx-platform you want to look into: