Warning headers allready sent tml

i received this warning when login and logout version: 6.3.9
Warning: Cannot modify header information – headers already sent by (output started at /wp-content/plugins/theme-my-login-custom.php:1) in /home4/spring/public_html/citymealdeals.co.uk/wp-includes/pluggable.php on line 678

Warning: Cannot modify header information – headers already sent by (output started at /wp-content/plugins/theme-my-login-custom.php:1) in /home4/spring/public_html/citymealdeals.co.uk/wp-includes/pluggable.php on line 679

Warning: Cannot modify header information – headers already sent by (output started at wp-content/plugins/theme-my-login-custom.php:1) in /home4/spring/public_html/citymealdeals.co.uk/wp-includes/pluggable.php on line 680

Warning: Cannot modify header information – headers already sent by (output started at /wp-content/plugins/theme-my-login-custom.php:1) in /home4/spring/public_html/citymealdeals.co.uk/wp-includes/pluggable.php on line 896

and i added a code in theme-myl-login-custom.php

<?php @ob_start();
@session_start();
?><?php function tml_user_register( $user_id ) {
if ( !empty( $_POST['first_name'] ) )		update_user_meta( $user_id, 'first_name', $_POST['first_name'] );
	if ( !empty( $_POST['last_name'] ) )
		update_user_meta( $user_id, 'last_name', $_POST['last_name'] );
	if ( !empty( $_POST['rpr_birth_day'] ) )
		update_user_meta( $user_id, 'rpr_birth_day', $_POST['rpr_birth_day'] );
	if ( !empty( $_POST['rpr_address'] ) )
		update_user_meta( $user_id, 'rpr_address', $_POST['rpr_address'] );
	if ( !empty( $_POST['usr_lat_val'] ) )
		update_user_meta( $user_id, 'usr_lat_val', $_POST['usr_lat_val'] );
	if ( !empty( $_POST['usr_long_val'] ) )
		update_user_meta( $user_id, 'usr_long_val', $_POST['usr_long_val'] );
}
add_action( 'user_register', 'tml_user_register');
?>
<?php
@ob_flush();
flush();?>

I love this plugin please give me solution so it not shows this warning
and i also test that whitespace problem that not works and also removing andadding this @ and all
please give me a solution as i put this in functions.php but i want to use in tmlcustom file as you wrote more organized form and i don’t want to off warning from php.ini
Thank you for this lovely plugin

https://ww.wp.xz.cn/plugins/theme-my-login/