Cannot implicitly convert type 'string' to 'bool'

Code is this
void OnColliderEnter(Collider other)
{
if (other.gameObject.tag = (“Pickup”))
{
other.gameObject.SetActive(false);
}
}
}
error is Cannot implicitly convert type ‘string’ to ‘bool’ on the red text.
Why?

= - assigning value to a variable
== - checking if the value of a variable is equal to something