Can use an iframe then read and fill the forms of the iframe? If no what other options do I have. If yes please explain a simple way

I need to use an iframe from another domain (for example Google.com iframe) then fill the forms (search input in Google and then submit form)

If there is any options that I can to this in JavaScript its very nice

For example I could use the Dom content of iframe like this

document.getelementbyid("main").innerhtml="text";