Cannot Install

[dudunegrinhu]

Your requirements could not be resolved to an installable set of packages.
Problem 1

• mpdf/mpdf v7.1.6 requires php ^5.6 || ~7.0.0 || ~7.1.0 || ~7.2.0 -> your PHP version (7.3.23) does not satisfy that requirement.
• mpdf/mpdf v7.1.6 requires php ^5.6 || ~7.0.0 || ~7.1.0 || ~7.2.0 -> your PHP version (7.3.23) does not satisfy that requirement.
• mpdf/mpdf v7.1.6 requires php ^5.6 || ~7.0.0 || ~7.1.0 || ~7.2.0 -> your PHP version (7.3.23) does not satisfy that requirement.
• Installation request for mpdf/mpdf (locked at v7.1.6) -> satisfiable by mpdf/mpdf[v7.1.6].

[kartik-v]

This is actually a dependency issue at your end on the third party mpdf library - it seems you are trying to install mpdf/mpdf which is of a older release v7.x -- while the latest release is v8.x. You may need to cross check your composer.json and dependencies.