how do you do Upon pressing asd, write y.e.s. to edit box (mfa inlcuded)

I've been trying this since yesterday, I looked at all the actions, worked with several objects, searched the forum a lot, downloaded several examples but none did the "simple" thing the title says XD

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This does the trick but Hey, that's not fair... that's trolling! XD

ooh! I almost forgot :o - please add a: Backspace will : delete the last 2 characters from right to left! this will complete the magic!

Rest assured that the help you give, turns back to the community as I will send the mfa as a gift to you all once I am done, for this is to serve the musical mfa I am working on for all of us!

I did it!!!!!!!!!!! a Fusion group whatsapp friend (he actually is one of us: member name: Fuuriokun) helped me and He even discarded the delimiters :o and made a working backspace delete! Since I just got it and it is a separate example (not making much sense alone), I will be working to implement it on my musical mfa and will be sharing soon so you all can benefit! Cheers to all!