Lip sync with seperate amp & speakers

[SoundsGood]

I'm trying to sort out the lip sync on my tv with amp and speakers. Whatever adjustment I try on the TV it still doesn't look right and it's driving me mad. I think it is the audio lagging behind the picture.

Apple have a solution for this but it looks like it needs an iPhone and I don't have one:
https://support.apple.com/en-us/HT210526

I'm thinking of buying another amp with sync adjustments but not sure if that's the best solution. An Android equivalent of the app above would be perfect.

TV is LG 55UJ634V, amp is a Topping MX3 fed through SPDIF

 

[SoundsGood]

It sounds like I need an AVR with ARC then.
I was hoping something like the Nvidia Shield Pro would do this kind of thing but apparently not.

 

[SoundsGood]

That video is great, I used the slo-mo function on my phone camera to get it set perfectly but unfortunately the delay on YouTube doesn't match some of the Netflix content I want to get in sync.