Rather, The catholic position ignores the Protestant doctrine of Sola Scriptura using only the Protestant Bible as the sole authority on this issue.
We do not have any injunction or example of praying to the departed believers.
The selected application of Sola Scriptura in your comment exposes its shortcoming. Not having an injunction or example in the Protestant Bible is insufficient to declare something true or false. There are no injunctions or examples of other truths you likely take for granted in the Protestant Bible either, principal among them Sola Scriptura itself, nor the Canon, with the last book in said Bible identifying all the preceding books to be included in said Bible.
I sure hope you're not an attorney in life.