What is this toilet part called?

[dontfollowme]

https://photos.app.goo.gl/KfR2FwFxMf1xvyZw8?

I have a toilet that is constantly running, it is a top flush and I reckon if I swap the part out that seems to be causing the issue it should fix it.

What do I need to be looking for?

Thanks

[dontfollowme]

I can't see anything resembling a cable but will have another look.

[dontfollowme]

Thanks for the further replies.

At it's worst it keeps filling until it eventually flows over the top of the white cylinder. The part that sprays the water out (about the site of a 5p in diameter) can be unscrewed. This part seems to be leaking.

At present I can just hear a gentle trickling into the bowl which is the water slowly over flowing into the white cylinder.

I may well just call a plumber when time allows.

[dontfollowme]

Thanks for the last suggestion - it is on a threaded rod so I adjusted the float. The water level just rose over it!

Case in point: https://photos.app.goo.gl/ER1GTD3gAQs51rgP8

[dontfollowme]

If I am replacing the part does this do I need to replace the whole assembly? E.g from the inlet whole upwards?

[dontfollowme]

Possibly but even when I hold the float in place this does not stop the tank from filling.