You can try the following suggestion by the @Admin to upload the files or data when you are still at Basic User Level.
(Input or output dataset) Paste your dataset into the post as a CSV, e.g.header1,header2,header1
a1,b1,c1
a2,b2,c2
or
(Input or output dataset) Upload the data to a public server and post a link here. This is best for larger datasets. swisstransfer.com is free and easy to use.