Getting error while running update query in postgresql

I am new to PostgreSQL. While running below update query I am getting below error.

update useremails ue 
SET ue.useinstitutionid=id.InstitutionID from instdomains id 
where ue.email REGEXP CONCAT('^.*[.@]',id.DomainMask,'$');

ERROR: syntax error at or near "REGEXP"

Mysql query

UPDATE useremails
JOIN instdomains ON useremails.email 
REGEXP CONCAT('^.*[.@]',instdomains.DomainMask,'$')
SET useremails.useinstitutionid=instdomains.InstitutionID;

I converted this query from mysql to Postgresql. How can rewrite this query in postgresql?

Copyright Notice：Content Author:「Moolya」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/68188686/getting-error-while-running-update-query-in-postgresql