Hello FaizM,
You can find some information here
ax.help.dynamics.com/.../set-up-the-advanced-bank-reconciliation-import-process
ax.help.dynamics.com/.../configure-advanced-bank-reconciliation
ax.help.dynamics.com/.../reconcile-bank-statements-using-advanced-bank-reconciliation
ax.help.dynamics.com/.../import-bank-statement-file-failed-or-has-incorrect-results
Yet, I have not found a sample import file on those pages.
Probably try asking your financial service provider / bank if they can provide you with a demo import file.
Hope this helps,
Ludwig