Translating error boxes? (see the picture)

Hello! I have a problem! How can i translating or modify those error boxes in the picture? Those appears when i click "send" in contact form but i haven't wrote my message or email adresses which in requrred.

I want delete the text "Your form has encountered a problem. Please scroll down to review."   Or if that can't delete, it would be translate to: "Ongelmia yhteydenotossa. Täytä vaadittavat kentät".

Next i want translate text Sähköpostiosoitteesi is required. to "Sähköpostiosoitteesi vaaditaan."

And i want translate text Viestisi is required. to "Viesti vaaditaan".

If somebody can help me, i would be thankful! 

See https://www.silvabokis.com/squarespace-tips/dynamic-translation-of-squarespace-form-error-messages

Thanks for the response paul2009. Unfortunately, that doesn't work. Where should i put that code?

On 10/20/2021 at 12:28 AM, Joni86 said:

Thanks for the response paul2009. Unfortunately, that doesn't work. Where should i put that code?

Add to Settings > Advanced > Code Injection > Footer