They mean that they are pushing to gain acceptance for their ideology by indoctrinating children, such as through early sex-education curricula, placement of sexually explicit materials in juvenile libraries, events such as Drag Queen Story Hour, and so forth.
The gay-rights, or LGBTQ-rights, or 2SLGBTQI+rights movement, or whichever jumble of letters you prefer to call it, ceased years ago to be about just gaining acceptance, or the ability to love whom one wishes. It's been absorbed into the Marxist-infused ideologies that have captured pedagogy, activism, leftist politics, even liberal theology.