Which version of the jquery library is used 2.x or 3.x? If 2.x can it be upgraded to use 3.x?

Hi! It uses core version of jQuery, so it is 3.x for now )
Please let me know if you face any issues with it )
Thanks!

Hi, SocialNicheGuru.

I plan to update the library version to 3.x.
But, now the module use the 2.x version of the library.
Link for download: https://raw.githubusercontent.com/patrickkunka/mixitup/v2/build/jquery.m...

Thank you for the report.

I've updated the functionality for using 3.x version of the library. Currently, I'm working on autoload mechanism for it.

I've added a new library version to the module dependencies using composer.
Also, you can download the library manually if you use zip version of the Drupal.
And, I've updated the "Installation" section in README.txt.

INSTALLATION:

For Drupal composer version:
1. Add this module to your project using composer command:
For stable version:
composer require 'drupal/mixitup_views:^1.0'

For development version:
composer require 'drupal/mixitup_views:1.x-dev'

2. Copy mixitup library from vendor/patrickkunka to your
libraries directory, default location web/libraries
3. Enable the module.
------------------------------------------------
For Drupal zip version:

1. Download MixItUp Views module.
2. Download MixItUp plugin from
https://github.com/patrickkunka/mixitup/archive/v3.3.0.zip and extract its
data to your project libraries directory, location /libraries
and rename the folder name to "mixitup"
3. Enable MixItUp Views module.
That's it :)

Also, to manage libraries in your project, you can use the module: Libraries API.
Link: https://www.drupal.org/project/libraries