while adding extract in a rac database if you receive this errror message

2020-08-25T15:02:58.794+0100  INFO    OGG-06604  Oracle GoldenGate Capture for Oracle, e1_wbr1.prm:  Database ICR01WBM CPU info: CPU Count 2, CPU Core Count 12, CPU Socket Count 2.
2020-08-25T15:02:59.229+0100  INFO    OGG-03522  Oracle GoldenGate Capture for Oracle, e1_wbr1.prm:  Setting session time zone to source database time zone 'Europe/London'.
2020-08-25T15:03:00.099+0100  INFO    OGG-01971  Oracle GoldenGate Capture for Oracle, e1_wbr1.prm:  The previous message, 'INFO OGG-03522', repeated 1 times.
2020-08-25T15:03:00.099+0100  ERROR   OGG-00868  Oracle GoldenGate Capture for Oracle, e1_wbr1.prm:  The number of Oracle redo threads (2) is not the same as the number of checkpoint threads (1). EXTRACT groups on RAC systems should be created with the THREADS parameter (e.g., ADD EXT <group name>, TRANLOG, THREADS 2, BEGIN...).
2020-08-25T15:03:00.099+0100  ERROR   OGG-01668  Oracle GoldenGate Capture for Oracle, e1_wbr1.prm:  PROCESS ABENDING.

then use threads parameter in extract add statement

add extract E1_WBR1, tranlog, begin now , THREADS 2