Missing OTB_INSTALL_DIR

which leads to :

root@921e43910e38:/home/otbuser# otbcli_BandMath                                                                                                                                                                                                                                                                                                                                                                                         
/opt/otbtf/bin/otbcli: 46: /opt/otbtf/bin/../otbenv.profile: Bad substitution                                                                                                                                                                                                                                                                                                                                                            
/opt/otbtf/bin/otbcli: 93: /opt/otbtf/bin/../otbenv.profile: source: not found                                                                                                                                                                                                                                                                                                                                                           
ERROR: Waiting for at least one parameter.                                                                                                                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                                                                                                                                                         
                                                                                                                                                                                                                                                                                                                                                                                                                                         
This is the BandMath application, version 9.0.0                                                                                                                                                                     
                                                                                                                                                                                                                    
...