We cannot append the survey URL with a specific language parameter directly and have the survey automatically displayed in that language. However, to specify the language in which a survey should be displayed using a survey link in QuestionPro, follow these steps:
Add Languages to Your Survey:
Ensure that you have added the desired languages to your survey. To do this, navigate to Surveys (Select Survey) » Edit » Languages and click on the Add Languages button. Select the languages you want to add and save the changes.
Use the Language-Specific Survey URL:
Once the language and its translations are added (either manually or using auto-translate), a unique survey URL is generated for each added language. You can use this language-specific URL for distribution. Refer screenshot for example https://prnt.sc/7TGYt1GdHR0q
Helpfile: https://www.questionpro.com/help/multilingual-surveys.html