Online and Local Backup Failed

I am a new member assigned to support the web site. The site have a few issues.

#1. It hasn’t been updated for sometime (WP, Plugin, Themes). I was able to update the plugins and Themes but with WP, I will need to perform a backup of the db and files. I noticed the log show the automatic scheduled online backup has been failing for years.
Error:

A transmission operation failed.
If the following error message is not clear as to the problem and the issue persists, please contact support providing the complete event log for the activity. Diagnostic information follows:

Failed at: /home/stmatt/public_html/wp-content/plugins/wponlinebackup/include/transmission.php(944)
A request failed for API Status.
Please ensure your blog is able to perform HTTPS requests to https://wordpress.backup-technology.com. You may need to contact your web host regarding this.
[Error Code http_request_failed] Could not resolve host: wordpress.backup-technology.com

I disconnect the online backup as an attempt to restart but unable to login to the online backup.

#2. I attempt to perform a manual local backup but it kept failing.
Error:

The activity failed: A filesystem operation failed.
20th Jan 2022 5.23.52 PM	 Error	A filesystem operation failed while processing 'Filesystem/public_html/wp-admin/error_log' (Size unknown) for backup.
If the following error message is not clear as to the problem and the issue persists, please contact support providing the complete event log for the activity. Diagnostic information follows:

Failed at: 1045(/home/stmatt/public_html/wp-content/plugins/wponlinebackup/include/files.php)
An error happened at: compressor_deflate.php(432)
filesize(): stat failed for /tmp/obfwh22Lj0
20th Jan 2022 5.11.08 PM	 Error	The activity failed: An error happened at: disk.php(223)
fopen(/home/stmatt/public_html/wp-content/plugins/wponlinebackup/tmp/backup.zip.8ab37df22e2f76523a936c9763034ea258cf23a5.rc.php): failed to open stream: No such file or directory
20th Jan 2022 5.09.22 PM	 Error	The activity failed: A filesystem operation failed.
20th Jan 2022 5.09.21 PM	 Error	A filesystem operation failed while processing 'Filesystem/public_html/wp-admin/error_log' (Size unknown) for backup.
If the following error message is not clear as to the problem and the issue persists, please contact support providing the complete event log for the activity. Diagnostic information follows:

Failed at: 1045(/home/stmatt/public_html/wp-content/plugins/wponlinebackup/include/files.php)
An error happened at: compressor_deflate.php(432)
filesize(): stat failed for /tmp/obfwH9NR7K

My Support Information:

Online Backup for WordPress Plugin Version 3.0.4
WordPress Version: 4.0.34 (standalone)
PHP Version: 5.5.38
Server Software: Apache
MySQL Server Version: 
MySQL Client Version: 1.0; MySQL Packet Size: 256?MiB
Memory: 256M; Post: 500M; Upload: 500M; Timeout: 30
Memory Changable: Yes; Admin Cache Size: 587.74?KiB
Status: 1 row, 6.03?KiB packet size, 572.46?KiB cache freed, 13.91?MiB memory used
Capabilities: hashcopy gzdeflate php5hash DES AES128 AES192 AES256
End of Information

The page I need help with: [log in to see the link]