Can we give Sadaqa (charity) with the intention of having our prayer answered? Hope you will answer this question.

Praise be to Allah, the Lord of the World; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Charity and alms are among the greatest pious acts. The person who gives alms and charity gets good reward and good compensation from Allah. Charity extinguishes the Wrath of Allah and keeps one away from a bad death. There are many other virtues for giving charity.
Finally, there is no objection in giving Sadaqah (alms) with the intention of having prayers answered. Because using good acts as means of approach to Allah is permissible and Sadaqah is a good deed.
Allah knows best.