The ETA portal lists USD 50 for countries outside South Asia and USD 20 for South Asian countries. It says the tourist ETA is free for 30 days for nationals of 40 listed countries from 25 May 2026, for Singapore and Seychelles (30 days) and the Maldives (90 days) under reciprocal and bilateral agreements, and for children of any nationality under 12 (up to 30 days).
Arriving from Iraq, no yellow fever certificate is required: WHO does not list Iraq as a transmission risk. It can still be demanded if you have been in a risk country shortly before arriving.
Driving on a Iraq license
Iraq is party to the 1968 Vienna Convention and Sri Lanka to the 1949 Geneva Convention. They share none, so no treaty obliges Sri Lanka to recognize an International Driving Permit issued in Iraq.
Whether a permit is required alongside your national license is set by national road law, which we have not checked for this pair.
International Health Regulations (2005), Article 36 and Annex 7; WHO International Travel and Health, Annex 1, 18 November 2022 (revised 3 January 2023)