After generally browsing Optiver's website, I found that they don't skimp on the positives of the company, but they rarely mention trading conditions, transaction fees, prices, etc. In other words, many descriptive texts and little numbers. This makes me feel they are not very sincere. As a result, I have no interest in trading here.

Definitely a bad broker, stealing clients with no executions of orders, slippage and other artifacts to take out your money. Highly regret choosing this broker, I was so stupid then.