sql – DBeaver Oracle: Extract the value of a tag from an xml

SELECT 
    :mybalise AS Balise
    ,SUBSTR(im.CONTENT,INSTR(im.CONTENT, :mybalise) + LENGTH(:mybalise) + 1,
    ((INSTR(im.CONTENT, '/' || '' || :mybalise)-2)
    - (INSTR(im.CONTENT, :mybalise) + LENGTH(:mybalise) + 1)+1)) AS BALISE_VALUE

FROM INBOX_MESSAGES im 
INNER JOIN PERSONS p2 ON p2.PERSON_ID =im.PERSON_ID 
    AND p2.INSS IN (83121526099)
WHERE im.TYPE = 'D054'
    AND im.OVERALL_START_DATE >= '01/07/2020' AND im.OVERALL_START_DATE <= '30/09/2020'
;