Thanks for writing in.
Would you mind sharing us more details of the error. Or Is there any error showing when installing the plugins?
Usually, plugins does not work because the PHP memory allocation is too low. Sometimes, hosting does not allow manual increase of memory allocation. It would be best that you will contact your hosting in regards to the increase.
Manual PHP Memory increase.
If still not working, you could share us your admin credentials so we could check your setup closer.
Don't forget to set it in a secure note.