There's multiple ways to start a convert process on Soundiiz interface.
Using Transfer tool
As a Free user, we are recommending you to use the Transfer tool, an easy and fast solution.
- Select Transfer under Tools
- Select a Category (Playlists, Tracks, Artists, Albums)
- Check elements you want to transfer
- Select the Destination platform
Using Platform to Platform tool
If you have subscribed to Soundiiz, you can use the Platform to Platform tool to be able to transfer all your datas in one time and leave it running in background !
- Select Platform to Platform under Tools
- Select the Source platform
- Select the Destination service
- Check Categories (Playlists, Tracks, Artists, Albums)
- Use Select items to check elements
- Confirm your selection to transfer
Using Your Library lists
You can also at any time do a right click or three dots 
and select Convert to feature to transfer any kind of element (Playlist, Track, Artist or Album) between music platforms.