Add Spells to "Core" Section of Character Sheet

Hello, I have watched a couple YT videos on adding spells and abilities to my character's Core section to be able to cast them during combat.  I'm looking at a Warlock I created and the UI won't let me drag Eldritch Blast from the Compendium into the "Attacks and Spellcasting" section of this character sheet and I can't figure out why.   When I drag it from the Compendium, the character sheet says, "accepting drop from Compendium," but then it isn't added.  The cantrip is in my character's "Spells" section, so he does know it.  I'm not sure how else I can roll this spell as an attack if it's not listed there.  Thanks for any help.

On the Spells tab, open the 'Eldritch Blast' spell (click on the 'i' icon), then click on the edit button ('gear icon') and make sure that the 'OUTPUT' field is set to 'ATTACK' and not 'SPELLCARD'. That's what toggles the spell showing up in the 'Attacks & Spellcasting' section on the Core tab. (This is known bug  for Eldritch Blast that was recently reported on the D&D 5E Character Sheet page.)

Jarren said: On the Spells tab, open the 'Eldritch Blast' spell (click on the 'i' icon), then click on the edit button ('gear icon') and make sure that the 'OUTPUT' field is set to 'ATTACK' and not 'SPELLCARD'. That's what toggles the spell showing up in the 'Attacks & Spellcasting' section on the Core tab. (This is known bug  for Eldritch Blast that was recently reported on the D&D 5E Character Sheet page.) Lifesaver, thanks Jarren!