As some appointments are published at national federations' websites (
http://cfa.com.cy/Gr/news/37623), I think it's OK to publish them here, too
PRELIMINARY ROUND (First Legs)27 June 2019, 19:30 CET - Differdange (Stade Municipal de la Ville de Differdange)
FC Progrčs Niederkorn (LUX) - Cardiff Metropolitan University FC (WAL)Referee: Luís Miguel do Nascimento Teixeira (AND)
Assistant Referee 1: Hugo Ricardo Jourdan Pereira (AND)
Assistant Referee 2: Joan Guiu Serra (AND)
Fourth Official: Pedro Filipe Carvalho da Costa (AND)
UEFA Referee Observer: Jari Maisonlahti (FIN)
UEFA Delegate: Wolfgang Thierrichter (AUT)
27 June 2019, 19:30 CET - Cardiff (Cardiff International Sports Stadium)
Barry Town United FC (WAL) - Cliftonville FC (NIR)Referee: Jason Lee Barcelo (GIB)
Assistant Referee 1: Andrew Mario Parody (GIB)
Assistant Referee 2: Daniel Gómez Gordillo (ESP)
Fourth Official: Patrick Canepa (GIB)
UEFA Referee Observer: Nicolae Grigorescu (ROU)
UEFA Delegate: Pierino Lardi (SUI)
Delegate Trainee: Stephen Williams (WAL)
27 June 2019, 20:00 CET - Andorra la Vella (Estadi Comunal)
UE Sant Juliŕ (AND) - Europa FC (GIB)Referee: Dragan Petrović (BIH)
Assistant Referee 1: Sreten Udovičić (BIH)
Assistant Referee 2: Damir Lazić (BIH)
Fourth Official: Zoran Grbić (BIH)
UEFA Referee Observer: Igor Șațchii (MDA)
UEFA Delegate: Camelia Nicolae (ROU)
27 June 2019, 20:00 CET - Tórshavn (Gundadalur)
Klaksvíkar Ítróttarfelag (FRO) - SP Tre Fiori (SMR)Referee: Robert Jenkins (WAL)
Assistant Referee 1: Ian Bird (WAL)
Assistant Referee 2: Martin Roberts (WAL)
Fourth Official: Bryn Markham-Jones (WAL)UEFA Referee Observer: Eyjólfur Ólafsson (ISL)
UEFA Delegate: Jean-François Crucke (BEL)
27 June 2019, 20:45 CET - Serravalle (San Marino Stadium)
SP La Fiorita (SMR) - UE Engordany (AND)Referee: Christophe Pires Martins (LUX)
Assistant Referee 1: Daniel Da Costa (LUX)
Assistant Referee 2: Joaquim Daniel Da Silva Gomes (LUX)
Fourth Official: Frank Bourgnon (LUX)
UEFA Referee Observer: Plarent Kotherja (ALB)
UEFA Delegate: István Huszár (HUN)
27 June 2019, 20:45 CET - Ballymena (The Showgrounds)
Ballymena United FC (NIR) - NSÍ Runavík (FRO)Referee: Athanásios Tzílos (GRE)
Assistant Referee 1: Chasán Koúla (GRE)
Assistant Referee 2: Vasílios Nikolakákis (GRE)
Fourth Official: Ioánnis Papadópoulos (GRE)
UEFA Referee Observer: John Ward (IRL)
UEFA Delegate: Emil Ubias (CZE)
27 June 2019, 20:45 CET - Pristina (Stadiumi Fadil Vokrri)
FC Prishtina (KOS) - St. Joseph's FC (GIB)Referee: Helgi Mikael Jónasson (ISL)
Assistant Referee 1: Birkir Sigurđarson (ISL)
Assistant Referee 2: Bryngeir Valdimarsson (ISL)
Fourth Official: Ţorvaldur Árnason (ISL)
UEFA Referee Observer: John Ferry (NIR)UEFA Delegate: Markus Stenger (GER)
Delegate Trainee: Arianit Ahmeti (KOS)