To install the Cato Certificate, download it from the Cato Client download portal and add it to your device's operating system certificate store.
Installing the Cato Certificate
You can download the Cato certificate from the Client download portal and install it on the required devices.
Select Cato Client, and then choose the operating system.

Installing the certificate will add it to the relevant operating system store (ie. Keychain for macOS, Certificate Management for Windows)
In case you're running third party tools which requires and manages its own certificate system, you'll need to import it there as well.
Few examples with references:
Java SE - You will be required to push the certificate to the Java cert store as well:

Or using the keytool - https://docs.oracle.com/javase/tutorial/security/toolsign/rstep2.html
InteliJ - https://intellij-support.jetbrains.com/hc/en-us/community/posts/206153629-How-to-add-a-SSL-root-certificate-to-IDEA-on-OS-X-?sort_by=votes
Git - http://stackoverflow.com/questions/9008309/how-do-i-set-git-ssl-no-verify-for-specific-repos-only
Firefox - https://wiki.mozilla.org/CA:AddRootToFirefox
Known Issues
Unable to install the certificate. Error: "Couldn't install because certificate file couldn't be read"
Workaround: Install a certificate from Settings/Additional Settings/Privacy/Install certificate from SD/Choose the relevant certificate
Installing Root CA Certificate to Firefox_ARCHIVED
Starting with version 120, Firefox can automatically trust third-party root certificates installed in the OS certificate store. For more information, see the Mozilla documentation.
To manually install the Cato certificate to Firefox:
From the browser options menu, click Settings.
Search for Certificates and click View Certificates.
In the Authorities tab, click Import.
Browse to where you stored the Cato root certificate and select it and click Open.
This should resolve any certificate issues with TLS inspection in Firefox.