To add a new product from a file, go to the "mymodels" page.
On the far right, beyond the trashcan, there are three dots. Click on them to get a popup menu.
First, check the file in 3D tools. You'll need to check in each material you plan to print the item in, although in the Versatile Plastics, you only need to check one of the colors.
If those work for you and you are good you proceed to the next step which is to return to the "mymodels" page.
Second, if you rename from the file page, then click on the three dots to get the popup menu. You should find an option to rename the file. BE SURE TO CHECK THE NAME. Long names are truncated without warning. When you are happy, go to the next step.
Finally, click on the three dots to get the popup menu. You should see the option to create a product. From there, it works much as it used to.
That is how it works at this point in the time-space continuum. Once this point has passed, things may change.
I hope this helps.
Jean