DS718+ '/opt': File exists`

[UnhealthyKraken]

Description of the problem

I'm a bit of a newbie when it comes to SSH, so I am unsure what to do here and how I have done anything wrong when I was following the instructions

Running the SSH Command

sudo install -m 4755 -o root -D /var/packages/aqc111/target/aqc111/spk_su /opt/sbin/spk_su

returns

install: cannot create directory '/opt': File exists

Description of your products

• DS718+
• Linux SynServer 4.4.180+ #42962 SMP Mon May 29 14:38:23 CST 2023 x86_64 GNU/Linux synology_apollolake_718+
• DSM 7.1.1-42962 Update 6

Description of your environment

• connect directly to a PC or using a hub
  • PC: NIC model name or chipset name
  • Hub: model name
• cable category (Cat.5e or Cat.6 or Cat.7)

Any help would be greatly appreciated

[bb-qq]

Probably there is /opt as symlink and it is inaccessible.