Update to use rollbar-php 4.0.1 (currently on 1.8.1)

[iugo-robert]

According to the rollbar dashboard it is saying that the WordPress plugin is currently using version 1.8.1.

It would be good if this could be updated to use 4.0.1.

[danielmorell]

Hey @iugo-robert, thanks for reaching out. The WordPress plugin should use 4.0.1 if your WordPress site is running on PHP 8. If you are still on PHP 7 than the highest version of the SDK used is 1.8.1.