At third level, a Barbarian can take the Path of the Totem Warrior, gaining (among others), the following feature:
Yours is a path that seeks attunement with the natural world, giving you a kinship with beasts. At 3rd level when you adopt this path, you gain the ability to cast the Beast Sense and Speak with Animals spells, but only as rituals.
Is a Barbarian Totem Warrior a Spellcaster, for the purpose of using magic items that require attunement by a Spellcaster?
If so, what is the spellcasting ability of a Totem Warrior, for the purpose of using magic items?
The following question and answers gloss over this particular case, but without giving a definitive answer for it.