connect OT@XEPDB1 fails: ORA-12154: TNS: could not resolve the connect identifier specified

Installed Oracle 18c XE.

Succesfull login: 

PS C:\Windows\system32> sqlplus / as sysdba

SQL*Plus: Release 18.0.0.0.0 - Production on Thu Sep 30 11:27:47 2021

Version 18.4.0.0.0

Copyright (c) 1982, 2018, Oracle.  All rights reserved.

Connected to:

Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production

Version 18.4.0.0.0

Succesfull alter session to XEPDB1:

SQL> alter session set container = xepdb1;

Session altered.

SQL> SHOW con_name;

CON_NAME

------------------------------

XEPDB1

Succesfull created test database:

However, after creating OT user and granting privilegs, connection failed:

SQL> CREATE USER OT IDENTIFIED BY Orcl1234;

User created.

SQL> GRANT CONNECT, RESOURCE, DBA TO OT;

Grant succeeded.

SQL> connect ot@xepdb1

Enter password:

ERROR:

ORA-12154: TNS:could not resolve the connect identifier specified