Do not limit the renew days to 60, it's just a default value.

buypass support 180 days.

acme.sh

@@ -40,7 +40,7 @@ VTYPE_ALPN="tls-alpn-01"
 
 LOCAL_ANY_ADDRESS="0.0.0.0"
 
-MAX_RENEW=60
+DEFAULT_RENEW=60
 
 DEFAULT_DNS_SLEEP=120
 
@@ -4267,8 +4267,8 @@ $_authorizations_map"
   Le_CertCreateTimeStr=$(date -u)
   _savedomainconf "Le_CertCreateTimeStr" "$Le_CertCreateTimeStr"
 
-  if [ -z "$Le_RenewalDays" ] || [ "$Le_RenewalDays" -lt "0" ] || [ "$Le_RenewalDays" -gt "$MAX_RENEW" ]; then
-    Le_RenewalDays="$MAX_RENEW"
+  if [ -z "$Le_RenewalDays" ] || [ "$Le_RenewalDays" -lt "0" ]; then
+    Le_RenewalDays="$DEFAULT_RENEW"
   else
     _savedomainconf "Le_RenewalDays" "$Le_RenewalDays"
   fi
@@ -5520,7 +5520,7 @@ Parameters:
   --useragent                       Specifies the user agent string. it will be saved for future use too.
   --accountemail                    Specifies the account email, only valid for the '--install' and '--update-account' command.
   --accountkey                      Specifies the account key path, only valid for the '--install' command.
-  --days                            Specifies the days to renew the cert when using '--issue' command. The max value is $MAX_RENEW days.
+  --days                            Specifies the days to renew the cert when using '--issue' command. The default value is $DEFAULT_RENEW days.
   --httpport                        Specifies the standalone listening port. Only valid if the server is behind a reverse proxy or load balancer.
   --tlsport                         Specifies the standalone tls listening port. Only valid if the server is behind a reverse proxy or load balancer.
   --local-address                   Specifies the standalone/tls server listening address, in case you have multiple ip addresses.