How can i open a question marked "pdf'' file?

[shanto244]

I downloaded a pdf file from facebook group. but when i was to open the file i noticed that it is not typical red coloured icon pdf file. it's the same size of a regular pdf file but had a question mark icon. I tried to open but then my phone replies that type file isn't supported.
Please say how can i open that file.

NB.- I am a 'Redmi note 8 pro' user

 

[B. Diddy]

Welcome to Android Central! How trustworthy is this group? Are you able to open it on a computer?

 

[Ben xfg]

I downloaded a pdf file from facebook group. but when i was to open the file i noticed that it is not typical red coloured icon pdf file. it's the same size of a regular pdf file but had a question mark icon. I tried to open but then my phone replies that type file isn't supported.
Please say how can i open that file.

NB.- I am a 'Redmi note 8 pro' user

Does the file name have the ".pdf" extension at the end? If not, you can edit the file name and add it, then it should know which app to use to open the file.