Generate own logic custom usermeta slug

functions.php

// Generate slug in format: {First Name}-{First letter of Last Name}~{hash}

function um_custom_generate_custom_slug( $user_obj ) {
	return strtolower( $user_obj->first_name . '-' . substr( $user_obj->last_name, 0, 1 ) . '~' . substr( strrev( md5( uniqid( 'um_user_hash' . $user_obj->ID, true ) . $user_obj->ID ) ), 0, 5 ) );
}

function um_update_custom_usermetaaa( $user_id ) {
	$permalink_base = UM()->options()->get( 'permalink_base' );
	if ( 'custom_meta' === $permalink_base ) {
		$custom_meta = UM()->options()->get( 'permalink_base_custom_meta' );
		if ( ! empty( $custom_meta ) ) {
			$user_obj = get_userdata( $user_id );
			if ( ! empty( $user_obj->first_name ) && ! empty( $user_obj->last_name ) ) {
				$db_value  = get_user_meta( $user_id, $custom_meta . '-names', true );
				$new_names = $user_obj->first_name . '-' . substr( $user_obj->last_name, 0, 1 );
				if ( $new_names !== $db_value ) {
					update_user_meta( $user_id, $custom_meta . '-names', $new_names );
					update_user_meta( $user_id, $custom_meta, um_custom_generate_custom_slug( $user_obj ) );
				}
			}
		}
	}
}
add_action( 'um_after_user_account_updated', 'um_update_custom_usermetaaa', 10 );


function um_update_custom_usermeta_user_profile( $to_update, $user_id ) {
	$permalink_base = UM()->options()->get( 'permalink_base' );
	if ( 'custom_meta' === $permalink_base ) {
		$custom_meta = UM()->options()->get( 'permalink_base_custom_meta' );
		if ( ! empty( $custom_meta ) ) {
			$user_obj = get_userdata( $user_id );
			if ( ! empty( $user_obj->first_name ) && ! empty( $user_obj->last_name ) ) {
				$db_value  = get_user_meta( $user_id, $custom_meta . '-names', true );
				$new_names = $user_obj->first_name . '-' . substr( $user_obj->last_name, 0, 1 );
				if ( $new_names !== $db_value ) {
					update_user_meta( $user_id, $custom_meta . '-names', $new_names );
					update_user_meta( $user_id, $custom_meta, um_custom_generate_custom_slug( $user_obj ) );
				}
			}
		}
	}
}
add_action( 'um_user_after_updating_profile', 'um_update_custom_usermeta_user_profile', 10, 2 );

function um_insert_custom_usermeta( $user_id ) {
	$permalink_base = UM()->options()->get( 'permalink_base' );
	if ( 'custom_meta' === $permalink_base ) {
		$custom_meta = UM()->options()->get( 'permalink_base_custom_meta' );
		if ( ! empty( $custom_meta ) ) {
			$user_obj = get_userdata( $user_id );
			if ( ! empty( $user_obj->first_name ) && ! empty( $user_obj->last_name ) ) {
				update_user_meta( $user_id, $custom_meta . '-names', $user_obj->first_name . '-' . substr( $user_obj->last_name, 0, 1 ) );
				update_user_meta( $user_id, $custom_meta, um_custom_generate_custom_slug( $user_obj ) );
			}
		}
	}
}
add_action( 'um_registration_complete', 'um_insert_custom_usermeta', 99 );

function um_insert_custom_usermeta_admin( $user_id ) {
	if ( ! is_admin() ) {
		return;
	}
	$permalink_base = UM()->options()->get( 'permalink_base' );
	if ( 'custom_meta' === $permalink_base ) {
		$custom_meta = UM()->options()->get( 'permalink_base_custom_meta' );
		if ( ! empty( $custom_meta ) ) {
			$user_obj = get_userdata( $user_id );
			if ( ! empty( $user_obj->first_name ) && ! empty( $user_obj->last_name ) ) {
				update_user_meta( $user_id, $custom_meta . '-names', $user_obj->first_name . '-' . substr( $user_obj->last_name, 0, 1 ) );
				update_user_meta( $user_id, $custom_meta, um_custom_generate_custom_slug( $user_obj ) );
			}
		}
	}
}
add_action( 'user_register', 'um_insert_custom_usermeta_admin', 999 );

function um_update_custom_usermeta_admin( $user_id ) {
	if ( ! is_admin() ) {
		return;
	}
	$permalink_base = UM()->options()->get( 'permalink_base' );
	if ( 'custom_meta' === $permalink_base ) {
		$custom_meta = UM()->options()->get( 'permalink_base_custom_meta' );
		if ( ! empty( $custom_meta ) ) {
			$user_obj = get_userdata( $user_id );
			if ( ! empty( $user_obj->first_name ) && ! empty( $user_obj->last_name ) ) {
				$db_value  = get_user_meta( $user_id, $custom_meta . '-names', true );
				$new_names = $user_obj->first_name . '-' . substr( $user_obj->last_name, 0, 1 );
				if ( $new_names !== $db_value ) {
					update_user_meta( $user_id, $custom_meta . '-names', $new_names );
					update_user_meta( $user_id, $custom_meta, um_custom_generate_custom_slug( $user_obj ) );
				}
			}
		}
	}
}
add_action( 'profile_update', 'um_update_custom_usermeta_admin', 999 );