I just want to ask if the entity specifically said to use the Chakra system or just said you had energy blockages? There are other models for working with the energy body if that’s your preference.
I use the Chinese Qi gong system, with 5 element theory, not Chakras, for example, it’s probably the main other system out there but I hear there are others, as well as Chakra systems with fewer and more than 7.
The way I would approach a block would not to practice a mantra focusing on the blocked area, which could just pile up more energy behind the block making it worse since these are for building the chakras, but visualize energy flowing through the area, and dissolving the block gently and easily. (If it was completely blocked that would make you sick, so chances are energy is flowing through it already, but not enough.)
It’s very helpful to move your body to keep energy flowing and clear blocks. Just going for walks where you can swing your arms would help, and here is a moving exercise and info focusing on the energy centers including the solar plexus (and thoat).
Blocks are often experiences and emotional energy condensed and stored in the body, so, be prepared for images and emotions to surface that could have caused this, and let them flow through and away without judging them.