Get all users who have a role

await message.guild.members.fetch()
        var memberIds;
        var data = [];
        // get all members with role 'Bootcamper'
        console.log('Getting all members with role \'Bootcamper\'...');
        console.log(camps.CodeCamp.Roles.Bootcamper);
        memberIds = message.guild.roles.cache.get(camps.CodeCamp.Roles.Bootcamper).members.map(m => m.user.id);
        console.log(memberIds);

        // send message
        await interaction.reply('Roles received.');

await message.guild.members.fetch()
        var memberIds;
        var data = [];
        // get all members with role 'Bootcamper'
        console.log('Getting all members with role \'Bootcamper\'...');
        console.log(camps.CodeCamp.Roles.Bootcamper);
        memberIds = message.guild.roles.cache.get(camps.CodeCamp.Roles.Bootcamper).members.map(m => m.user.id);
        console.log(memberIds);

        // send message
        await interaction.reply('Roles received.');

Cannot read properties of undefined (reading 'members')

Cannot read properties of undefined (reading 'members')

memberIds = interaction.guild.roles.cache.get(camps.CodeCamp.Roles.Bootcamper).members;

memberIds = interaction.guild.roles.cache.get(camps.CodeCamp.Roles.Bootcamper).members;

Cannot read properties of undefined (reading 'members')

Cannot read properties of undefined (reading 'members')

{
    "camps": {
        "CodeCamp": {
            ...
            "Roles": {
...
                "Bootcamper": integer
            }

{
    "camps": {
        "CodeCamp": {
            ...
            "Roles": {
...
                "Bootcamper": integer
            }