Hi Freddie
apologies, I forgot to mention that you also need to download the correct locale for the language that you want your form in. By default the CF7 plugin installs the locale of your dashboard.
To get other locales you need to download them from the WP translation site.
Click on the row of the language you are looking for, it will take you to that language’s page, scroll to the bottom of the page and you will see an Export link. from the drop down, select Machine Object format (.mo).
Unzip the file you downloaded and place the contact-form-7-<locale>.mo
file in the languages
folder of the CF7 plugin directory.
Then make sure you use the same locale code in your URL.
For example, if you downloaded contact-form-7-en_GB.mo
, then the url to create a form in that locale will be,
https://<your-website-domain>/wp-admin/admin.php?page=wpcf7-new&locale=en_GB
hope that helps. Note, not all translations are complete, some locale have missing text which default to the initial locale. If you wish to change the translation, you can download the POT file and use the Poedit tool to modify/add translation which can then save as .mo
file again.