Kitchen Mixer Spout No Longer Able to Move / Turn

Hello, I have a kitchen mixer tap that is currently very stiff to turn from side to side (the spout part). If I do try to turn the spout, the swivel base that is attached to the sink also turns. Obviously I don't want to damage my sink so I never try to turn the spout any more, but it would be nice to have it moving freely again.

I have attached a pic of the tap.

Any advice on whether this can be easily serviced/ how to service the tap would be much appreciated.

Here is a link to the tap bought with a kitchen from Wren (fitted in 2016):
Kronos Tap Chrome - High/Low Pressure | Wren Kitchens

It simply needs lubricating. Silicone grease (food safe type)

Usually have a tiny grub screw (Allen screw) in top rear of mixer body holding the spout from pulling up

As above needs lubrication