The sequencer doesn’t a direct fade/dissolve.
I would suggest adding a plane with the material set to use your title.
And then make a material with Opacity which can then be keyed in Sequencer.
Make a simple material, set Blend Mode to Transparent, add a texture into the base color of your title and add a scaler to the Opacity. You’ll animate this in Sequencer between 0 and 1.
Here’s more info on how to animate a material in Sequencer