Mounting a pull up bar on hollow concrete block wall
Please be very careful to ensure that there is sufficient block wall above your attachment point to stop the whole wall toppling forward under load.

Children have been killed by basketball hoops fixed to brick fascia's above garage doors when they slam-dunked and swung on the hoop. The brick fascia collapsed forward onto the child crushing them.

I expect you want at least several feet of wall above your attachment point, even better if the roof is providing good downforce to hold the wall together.