how to check paid estimated taxes 2021

I started working as contractor starting this year around May . I knew I have to pay quarterly taxes back in June when June 15 approaching I was trying to use Turbo Taxes but I couldn't proceed because it keeps pointing me back 2020 taxes with due time approaching I ended up asking a friend's CPA to  calculate my estimated taxes for 2021 and I ended paying it on pay1040.com using CC since I don't have money during that time I received confirmation # from pay1040 but nothing from IRS is that normal ? I wander how can I make sure IRS have received my payments ? I sent emails to pay1040 but receive nothing.  there is no human agent from their tech support as well. please advise.