Oracle IMPDP job ORA-30036 unable to extend segment by 8 in undo tablespace 'UNDOTBS1'
Ensure that the default undo tablespace has enough capacity.

Based on your output, I see 3 tablespaces with 2GB of size.
Perhaps one of them is the default assigned UNDO and auto extend is off.

Another prediction is that the default undo could be another tablespace with a different name, the query executed does not indicate the default undo but rather checks the tablespaces named with 'UNDO'.

You can check the default undo tablespace using the below query

select value from v$parameter where name like 'undo_tablespace';