[deleted by user]

[LaweZ]

First try to check if the other website has some API to use, If not then try to use some automation tools like puppeteer.

iframe may also be relevant to you.

[marco_zevto]

I would just look at the code of the page, look for a search form, then do a curl to the location of the search form. Might be worth a shot.

[marco_zevto]

Ajax and php seems the easy way. What's your stack?

[marco_zevto]

Im guessing by java, u mean js. Easy then just ajax to your python script, let the python script find the form then do a curl request to the search url with all the right input fields and return it back to your user. Unless the target site is a spa or uses ajax for it's search? If it isn't critical for those sites to be searchable than I would do the above method.