Disregard this, read Potato Chips reply and what hosseinimr93 also replied after him.
Do not be deceived, the accelerator is not free like people are thinking. If the mempool is not congested is only the time you can enjoy the accelerator when it is not needed, but when the mempool becomes congested, you will be disappointed by the accelerator.
I wanted to use the accelerator since many days ago after bitcoin halving but I will always not be able to submit the txid on time. If I am able to submit the txid on time, it would displayed that the captcha is not correct. I tried it just now and several times before but the same incorrect captcha. I am certain that the captcha is correctly solved, bit it will displayed as incorrect.
Once 5 seconds is over in every hour, you will not be able to use the free accelerator again until the next hour but you will see this displayed by the accelerator:
Your free accelerator quota has run out, please choose the paid service if you need acceleration.
Either you will not be able to solve the captcha and wait for the next hour again and again, but if you are able to about to submit the txid, it will dispay captcha not correctly solved when I am certain that I solved it correctly again and again.
During congestion people will always complain about people that are using bots which are faster to submit txids before people that are submitting it manually on their own. But who knows if it is the site that is manipulating. Few weeks or months ago, you can use free accelerator on the site without registration, but which is no more possible. If you want to use free accelerator on the site, you have to register.
When I saw that registration is need, I was thinking it was done to make people not to be able to use bot on the site but when mempool has been congested lately, I saw that I was very wrong. The site is now displaying to people to use the paid accelerator and the free accelerator is not acceptable. They are just using the free accelerator to lure people to use their paid accelerator. We should not be deceived by ViaBTC free accelerator.