Kailangan ba i-submit ang bus/airline tickets to support liquidation of cash advance for travel?

Q: Good day! Ask ko Lang Sana kung anu ba legal basis ng mga COA and accountant para irequire yun mga mag travel na govt personnel or employees na need nila e attached yun actual tickets for the said travels. My basis po ba Yun? Salamat tlga ng marami. Pki hide nalang po ID ko if ever man. 🙏✌️😇 Thank you!