On Tevijjavacchagotta Sutta the Buddha said that in the last ninety-one aeons, no fatalist who denies the power of volitional acts,
has ever gone to heaven, except one, who happened to follow the
doctrine of kamma and of morally effective deeds.
OK, if that is the case. I have not read this sutta.
How does this power of volitional act or volitional act happen with in the frame work of Pratītyasamutpāda?
It happens at the 4th condition. It will also arise with craving. Why don't you read the Pali suttas?
Feeling, perception, volition, contact and attention — these are called mentality (nama).
SN 12.2; MN 9
When the nutriment of volition is comprehended, the three forms of craving [for sensuality, for becoming, and for
non-becoming] are comprehended.
My intention is not to discuss about non-self rather about the volitional act done by the self-doer as explained in Attakārī Sutta.
Also not so much about the change or motion, the being stepping forward or backward, but the volition or intention that brought about
Pratītyasamutpāda states that everything except Nirvana are conditioned,
It does not. Paticcasamuppada described the 12 conditions for the arising of sorrow, lamentation, pain, grief & despair.
and from ignorance (Avijjā) comes mental formations (Saṅkhāra)
which includes volition.
'Sankhara' does not include 'volition' because the 'sankhara' are non-volitional since they arise from ignorance. 'Sankhara' are defined as the 'body, verbal & mind conditioner', which are defined in MN 44 as the breathing in & out; initial & discursive thought; and perception & feeling. This does not include volition.
For example, when you try to meditate & all of those discursive thoughts are spinning out of control in your head (which also make your breathing agitated), this is 'sankhara' in Paticcasamuppada. This obviously is not 'volition' since you are not 'choosing' to have these out-of-control thoughts.
Volition occurs at the 4th condition, nama-rupa (and also at the 8th condition, craving).
So if every mental formation is conditioned by ignorance including human volition (choice)
This is not true. Paticcasamuppada only describes when volition is tainted by ignorance. It does not describe when volition is guided by wisdom.
how come a being by choice, which is
volition, which has ignorance at its base root out ignorance?
On the other hand, if volition (choice) is not conditioned by ignorance, then the beings choice is out side Pratītyasamutpāda which
has ignorance at its starting point?
Correct. Paticcasamuppada is called "the wrong path" (SN 12.3). Paticcasamuppada does not describe wise or right intention/volition, which is the right path.
Similarly, if the answer is yes and no, this still implies that volition (choice) can be out side Pratītyasamutpāda?
Yes. Correct. Very good.
There are two types of volition: ignorant volition & wise volition.