It can only be set on the web application.
This feature is exclusively for administrators of the company's account.
In 3 steps:
Access the account preferences by clicking at the bottom of the menu on your profile.
In the preferences menu, go to "Tenders" and then to the "Messages" sub-menu.
In this section, create or modify the default message that companies will receive when you request a quote.
Don't forget to save in the top right corner!