UPDATE
I found the information here from Madhackers very useful
https://www.matterhackers.com/news/how-to-succeed-when-printing-with-flexible-filament
or use this **LINK**
I bought some Priline TPU filament from Amazon and spent a few hours finding the best setting printing a variety of 20mm cubes.
The the standard Leapfrog Creatr feed mechanism seems to be able to feed the flexible filament OK so far.
I created a profile for the Filament that had a higher temp than PLA [240 C] and increased the Extrusion multiplier to 1.15.
The setting for the Print profile was created using a much lower speed setting , Max speed 30mm/sec down to 10 mm/sec.
There is probably scope for tweeking as I print different projects.
Steve