Ocr free version API 3 concurrent connections at the same time allowd problem

hello, i’m majored in CS . and i make project about maching learning.
First of all i have to use Ocr api to covert some image to text.
but when i used this api to convert massive images or more than 3 images,
i got error
For this API KEY only 3 concurrent connections at the same time allowed. Contact support if you need more.’

is this mean i have to use premere version API?

PLZ help me how to solve this problem asap

thank you

Being discussed here as a bug: Only 3 concurrent connections allowed