The Bulgarian parliament has banned the sending of its military to Ukraine, except for missions within NATO and other international organizations.
The adopted declaration also calls for a diplomatic settlement of the war and underlines Bulgaria's commitment to supporting de-escalation initiatives and peace talks.
That means, they WILL NOT not go in as EU "peacekeepers." They only technically could go in as NATO or UN peacekeepers, but NATO was forbidden by Trump, and UN will likely be vetoed by Russia.
So Bulgaria has chosen wisely, and publicly made clear they are OUT.