How to change “Foxitreader Document” to normal PDF format?

I am using Ubuntu 18.04 LTS version.Few days ago I have installed FoxitReader through terminal but due to some reasons I have uninstalled it but now when I download PDF file from internet it default shows “FoxitReader Document” type instead of “PDF document” and since I have uninstalled FoxitReader, I can’t open such files with Okular or Document Viewer so can anyone please help me??

I want to change all files to PDF document files and I don’t want to install FoxitReader again.enter image description here