Setting ulimit values without /etc/security/limits.conf

Hello,

I'm running into problems with virtual memory on my router. I need to increase the virtual memory limit of one my processes to enable rclone to sync after successful torrent download.

See here:
https://forum.transmissionbt.com/viewtopic.php?f=2&t=18916&p=76029&sid=eaf4488724f55386c3a97e7dccb20ef7#p76029

What do I need to do given that there is no /etc/security/limits.conf I can edit to change the amount of RAM? Is there any other way to increase ulimit -v for a specific user?