Querying objects in a list by class type vs string identifier - Best practices

I have a class Character who has a list of Spell objects that he can cast.

abstract class Spell {
    name: string
    manaCost: number

    abstract cast() { ... }
}

class InvisibilitySpell extends Spell { ... }
class FireballSpell extends Spell { ... }

class Character {
    mana: number
    spells: Spell[]

    addSpell(spell: Spell) {
        this.spells.push(spell)
    }
}

Casting spells requires accessing the correct spell by index in the .spells[] array

let char = new Character()
char.addSpell(new InvisibilitySpell())
char.addSpell(new FireballSpell())
char.spells[0].cast() // casts Invisibility spell
char.spells[1].cast() // casts Fireball spell

To improve the ergonomics of the interface and implement mana requirements, I plan on adding a castSpell method to the Character class that will delegate to the correct spell object, but I am not sure what the best practice is for handling the query.

I could query by the string value of the .name

class Character {
    ...
    castSpell(spellName: string) {
        let spell = this.spells.find(spell => spell.name === spellName)
        if (spell && spell.manaCost <= this.mana) {
            spell.cast()
        }
    }
}

char.castSpell('Invisibility')

Or I could query by the type itself

class Character {
    ...
    castSpell(spellType: typeof Spell) {
        let spell = this.spells.find(spell => spell instanceof spellType)
        if (spell && spell.manaCost <= this.mana) {
            spell.cast()
        }
    }
}

import { InvisibilitySpell } from './spells/InvisibilitySpell'

char.castSpell(InvisibilitySpell)

What software design considerations or technical implications might there be for doing one over the other, and are there approaches even better than these two?