Hello @DahshengSong and welcome to the SAS Support Communities!
Either it's just because you misspelled the procedure name (which is causalmed) or your SAS/STAT version is only 14.2 or older. PROC CAUSALMED was introduced in SAS/STAT 14.3. To find out your version number you can submit:
proc product_status;
run;
The 2025 SAS Hackathon has begun!
It's finally time to hack! Remember to visit the SAS Hacker's Hub regularly for news and updates.
ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.