UNKNOWN_EXCEPTION, portal account owner must have a role: In Future Method

When a contact is created I am trying to create community portal user. So first I wrote the user creation code in trigger itself but I got the error 'MIXED_DML_OPERATION'. So I moved my user creation code to a future method
and my code is like below

Trigger handler Code

public void AfterInsert(List<Sobject> newMap){
        try{
        set<ID> conids = new set<ID>();
            for(Contact c : (List<Contact>) newMap){                
                if(Schema.getGlobalDescribe().get('Contact').getDescribe().getRecordTypeInfosById().get(c.RecordTypeId).getName().toUppercase() =='PROVIDERS'){
                    conids.add(c.id);           
            }  
        }
        
      
        CreateUsers.createCommunityUsers(conids);
        }
        catch(Exception Ex){
         
        }
    }

and here is my Future method class code

public class CreateUsers {
    @future 
    public static void createCommunityUsers(set<Id> setContactids)
    {
        List<contact> conlist = [select id,email,firstName,lastname from Contact where Id IN : setContactids];
       
         List<Profile> profileList = [Select Id from Profile where Name= 'Provider Customer Community Plus User' limit 1];
         List<UserRole> roleList = [Select Id from UserRole where Name= 'Customer Person Account' limit 1];


            List<user> usr = new List<user>();
            Database.DMLOptions dmo = new Database.DMLOptions();
                dmo.EmailHeader.triggerUserEmail = true;       
                dmo.EmailHeader.triggerOtherEmail = true;
                dmo.EmailHeader.triggerAutoResponseEmail = true;       
            
            for(Contact con : conlist){              
                string nick = con.email!=null?con.email.substring(0, con.email.indexOf('@')):''; nick += Datetime.now().getTime();       
                User newUser = new User(
                                alias = con.lastname,
                                email = con.email,
                                emailencodingkey = 'UTF-8',
                                firstname = con.firstName,
                                lastname = con.lastname,
                                languagelocalekey = 'en_US',
                                localesidkey = 'en_US',
                                contactId = con.Id,
                                timezonesidkey = 'America/Los_Angeles',
                                username = con.email+ Datetime.now().getTime(),
                                UserRoleId = roleList[0].Id,
                                CommunityNickname = nick,
                                ProfileId =profileList[0].Id,                           
                                IsActive = true);     
                                newUser.setOptions(dmo);                          
                                usr.add(newUser);        
                }            
            Insert usr;
    }
}

But I am always getting

FIELD_INTEGRITY_EXCEPTION, Invalid role assignment.: 

and if I remove this line of code

  UserRoleId = roleList[0].Id,

I am getting

UNKNOWN_EXCEPTION, portal account owner must have a role

Account record is also mapped properly to that contact
Here is the debug trace

Contact:{Id=0033K00000GlwBJQAZ, [email protected], FirstName=Global, LastName=Test, AccountId=0013K00000kxIf7QAE}


User:{Alias=Test, [email protected], EmailEncodingKey=UTF-8, FirstName=Global, LastName=Test, LanguageLocaleKey=en_US, LocaleSidKey=en_US, ContactId=0033K00000GlwBJQAZ, TimeZoneSidKey=America/Los_Angeles, [email protected], CommunityNickname=solutions1632245022446, ProfileId=00e3K000000E0esQAC, UserRoleId=00E3K000000SRifUAG, IsActive=true}