How to correctly define this Observation Space for the custom Gym environment I am creating using Gym.Scpaces.Box?

I am trying to implement DDPG algorithm of the Paper.

Here in the image below, gk[n] and rk[n] are KxM matrices of real values. Theta[n] and v[n] are arrays of size M.

I want to write correct code to specify state/observation space in my custom environment.

Since the data type input to the neural network needs to be unified, the state array can be expressed as

observation_space = spaces.Box(low=0, high=1, shape=(K, M), dtype=np.float16......)

I am stuck.

If you use stable-baselines3, you may use a Dict observation space filled with Boxes with meaningful limits for all your vectors and matrices (if limits are unknown, you may always use +inf/-inf). The code could be something like:

from gym import Env
from gym.spaces import Box, Dict

class MySuperGymEnv(Env):
  def __init__(self):
    ...
    spaces = {
       'theta': Box(low=0, high=1, shape=(99,), dtype=np.float32),
       'g': Box(low=0, high=255, shape=(100,200), dtype=np.float32),
       ...
    }
    self.observation_space = Dict(spaces)
    ...