heredoc php functions for select element

Question

I understand that calling PHP functions within HEREDOC strings can be tricky and I have looked at some of the previous answers on here and tried to implement them without success.

I have a function that outputs enum data type to a drop-down list using the <select> tag. The code works well when not using HEREDOC strings.

However I would like to get this working within the HEREDOC delimiter but I am having an issue calling the function and getting the output into the dropdown.

Any steering would be appreciated.

function show_enum_in_dropdownbox() {
        
    $query = query("SHOW COLUMNS FROM members_personal_details WHERE Field = 'enum_region'"); 
    
    while ($row = mysqli_fetch_row($query)) {
                
        foreach(explode("','",substr($row[1],6,-2)) as $option) {
                    
            print("<option>$option</option>");
            
    
        } // ends foreach
        
        
    } // ends while loop
    
    
        
} // ends function

Heredoc

$myenums = <<<DELIMETER
    
    
    

<select name="region" id="" class="form-control" style="min-width: 100%; max-height: 200px;" required> 
        
                                                    
        <option value="">PLEASE SELECT REGION</option>
                                                
                 <?php show_enum_in_dropdownbox(); ?>
                                                                                 
        
</select>
    
    
    
DELIMETER;
    
echo $myenums;