From $q_1$

$d$ :

Explanation:

Handle $\text{'}$b$\text{'}$s and $\text{'}$a$\text{'}$s by looping within $q_1.$

On seeing an empty string while the stack has $Z,$ transition to $q_2$

without modifying the stack.

Acceptance:

The automaton accepts when it reaches the accepting state $q_2$

with an empty stack.

Step $3$

The DPDA$($Deterministic Pushdown Automaton$)$ for the Language

$L=\{\begin{array}{c}{a}^n{b}^m\text{:}m=n\\ ?\end{array}$ or $\{$:$,n=m+2,n>0\}$ is: