I think “from” would be the most appropriate preposition when talking about the institution where you obtained your qualification. Eg “I have a Master’s degree from the University of Melbourne” or alternatively “I completed a Bachelor of Science at the University of Sydney”. In this case though, do you mean that the course was run by Google the company or that you found a site to take an online course by searching Google? Because if you were to say I have a digital marketing course from Google, to me it is not quite clear whether Google is running the course or if you found the course through Google. If the course is run by Google I would probably say something like “I have completed a digital marketing course run by Google.”

How about? I have recently been certified as a digital marketing specialist from Google course.

With pattens, you can do with ease.

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