To edit the text, click on "Objects", then you will see an object named "text_shape". Right click on it and select "Edit Text". Note that it is a bit buggy. If you re-arrange the objects and leave the "Align to Y axis" box checked, it may mess up the text. If that happens, it's easier to just start over rather than try to fix it.
Looking great. May i ask you to add the name of my Wife and Daughters? Nelli, Alexandra, Lina, Maryam, Malea. That would be awesome!! Greetings from Germany.
You have to download a font you like (i.e. from DaFont.com), install it, go in fusion360 and type all the alphabet and extrude every single letter; then save as .stl everyone of it and then load in slicer the letter you need and manually combine them and then print.