Import multiple CSV files, allowing relationships, refresh via Power BI Service, using FREE edition

glauberferreira You're probably stuck in the middle there. I know there are several ideas posted for this and you can vote for them and wait to be implement. Considering Azure is also great alternative as it will give you live connection without needing to worry about schedule refresh.

One possible solution I can suggest to you since you mentioned it is in prototype phase is to get upgraded to free trial of Pro version. They don't need any of your credit card details or stuff like that. Simply download and install gateway and start using it and next time you login to powerbi.com it will say you're using Pro features and so upgrade for free trial. At the end of first month you can also extend trial and I have been using Pro free trial for few months now.

This way you get couple of months to evaluate your design and maybe by that time refresh for csv is supported.