Can we use Adobe stock photos (that I have acquired license of and is free) for an online course that I am creating to publish? It will be used/incorporated in a PowerPoint slide
If not, what kind of measures can I take to be able to do so?
Free assets are licensed under a standard licence. You will need to consult your lawyer for juristic advice on this. I can't see, based on your information, a clear yes or no.
Look here for more information on licensing: https://community.adobe.com/t5/stock/links-for-licensing-terms/td-p/11366788
(Disclaimer: As always with licensing, this is my interpretation of the rules. I think they are correct and advice is based on reading and interpreting the licence terms and on fair use for both the buyer and the artist/stock company, but I cannot rule out that my interpretation is wrong. I'm not an Adobe employee).
Thank you so much, Abambo!