How to optimize this campaign?))

[IgorSia]

Hello mates))
I am having difficulty optimizing this campaign.
I don't even know what to do.
Here are the stats:
Websites

browsers:

quality:

states:

OS versions:

I don't know how to optimize this campaign, I look at the metrics and I need to blacklist all sites and turn off all parameters. At the same time, I understand that I will turn off all sources where most conversions come from. ROI is good overall, but how to improve this indicator. I think many beginners will be interested to know what to do in such a situation.
Before optimization, I played with landing pages and left only two of them.
Also I have disabled several devices.